The climate of Africa is a range of climates such as the equatorial climate, the tropical wet and dry climate, the tropical monsoon climate, the semi-arid climate (semi-desert and steppe), the desert climate (hyper-arid and arid), the humid subtropical climate, and the subtropical highland climate. Temperate climates are rare across the continent except at very high elevations and along the fringes. In fact, the climate of Africa is more variable by rainfall amount than by temperatures, which are consistently high. African deserts are the sunniest and the driest parts of the continent, owing to the prevailing presence of the subtropical ridge with subsiding, hot, dry air masses. Africa holds many heat-related records: the continent has the hottest extended region year-round, the areas with the hottest summer climate, the highest sunshine duration, and more.
Owing to Africa's position across equatorial and subtropical latitudes in both the northern and southern hemisphere, several different climate types can be found within it. The continent mainly lies within the intertropical zone between the Tropic of Cancer and the Tropic of Capricorn, hence its interesting density of humidity. Precipitation intensity is always high, and it is a hot continent. Warm and hot climates prevail all over Africa, but mostly the northern part is marked by aridity and high temperatures. Only the northernmost and the southernmost fringes of the continent have a Mediterranean climate. The equator runs through the middle of Africa, as do the Tropic of Cancer and the Tropic of Capricorn, making Africa the most tropical continent.
Globally, heating of the earth near the equator leads to large amounts of upward motion and convection along the monsoon trough or Intertropical Convergence Zone. The divergence over the near-equatorial trough leads to air rising and moving away from the equator aloft. As it moves towards the Mid-Latitudes, the air cools and sinks, which leads to subsidence near the 30th parallel of both hemispheres. This circulation is known as the Hadley cell and leads to the formation of the subtropical ridge. [2] Many of the world's deserts are caused by these climatological high-pressure areas, [3] including the Sahara Desert.
Temperatures are hottest within the Sahara regions of Algeria and Mali, [4] and coolest across the south and at elevation within the topography across the eastern and northwest sections of the continent. The hottest average temperature on Earth is at Dallol, Ethiopia, which averages a temperature of 33.9 °C (93.0 °F) throughout the year. [5] The hottest temperature recorded within Africa, which was also the world record, was 57.8 °C (136.0 °F) at 'Aziziya, Libya, on 13 September 1922. This was later proven to be false, being derived from an inaccurate reading of a thermometer. The world's hottest place is in fact Death Valley, in California. [6] [7] [8] Apparent temperatures, combining the effect of the temperature and humidity, along the Red Sea coast of Eritrea and Gulf of Aden coast of Somalia range between 57 °C (135 °F) and 63 °C (145 °F) during the afternoon hours. [4] The lowest temperature measured within Africa was −24 °C (−11 °F) at Ifrane, Morocco, on 11 February 1935. [9] Nevertheless, the major part of Africa experiences extreme heat during much of the year, especially the deserts, semi-deserts, steppes and savannas. The African deserts are arguably the hottest places on Earth, especially the Sahara Desert and the Danakil Desert, located in the Horn of Africa.
The mid-level African easterly jet stream north of the equator is considered to play a crucial role in the West African monsoon, [10] and helps form the tropical waves which march across the tropical Atlantic and the eastern part of the Pacific during the warm season. [11] The jet exhibits both barotropic and baroclinic instability, which produces synoptic-scale, westward-propagating disturbances in the jet known as African easterly waves, or tropical waves. A small number of mesoscale storm systems embedded in these waves develop into tropical cyclones after they move from west Africa into the tropical Atlantic, mainly during August and September. When the jet lies south of normal during the peak months of the Atlantic hurricane season, tropical cyclone formation is suppressed. [12]
Low-level jets are fast winds which form close to the surface (within 1.5 km). They affect a number of climate processes across Africa. The Somali Low-level Jet, [13] which forms of the coast of East Africa, contributes to the existence of the Somali Desert. [14] [15] Low-level jets of the Sahara are known to be important for raising dust off the dry desert surface. For example, the low-level jet over Chad, [16] is the driver of dust emission from the Bodélé Depression, the largest source of atmospheric dust on the planet. [17] Easterly low-level jets which form in river valleys across the East African Rift System supply millions of tonnes of water vapour originating from the Indian Ocean across East Africa and to the Congo rainforest. [18] In doing so, they leave East Africa unusually dry for its latitude. [19] Low-level southwesterlies emanating from the Gulf of Guinea are the key moisture source for the West African monsoon in northern hemisphere summer. [20]
The Tropical Easterly Jet, which forms high up in the atmosphere, 15-17 km above the surface, is another important factor. Variations to the speed and position of this jet stream can affect rainfall in the Congo Basin and the Sahel. [21]
Great parts of North Africa and Southern Africa as well as the whole Horn of Africa mainly have a hot desert climate, or a hot semi-arid climate for the wetter locations. The Sahara Desert in North Africa is the largest hot desert in the world and is one of the hottest, driest and sunniest places on Earth. Located just south of the Sahara is a narrow semi-desert steppe (a semi-arid region) called the Sahel, while Africa's most southern areas contain both savanna plains, and its central portion, including the Congo Basin, contains very dense jungle (rainforest) regions. The western equatorial region is the wettest portion of the continent. Annually, the rain belt across the continent moves northward into Sub-Saharan Africa by August, then passes back southward into south-central Africa by March. [22] Areas with a savannah climate in Sub-Saharan Africa, such as Ghana, Burkina Faso, [23] [24] Darfur, [25] Eritrea, [26] Ethiopia, [27] and Botswana have a distinct rainy season. [28] El Nino results in drier-than-normal conditions in Southern Africa from December to February, and wetter-than-normal conditions in equatorial East Africa over the same period. [29]
In Madagascar, trade winds bring moisture up the eastern slopes of the island, which is deposited as rainfall, and bring drier downsloped winds to areas south and west, leaving the western sections of the island in a rain shadow. This leads to significantly more rainfall over northeast sections of Madagascar than its southwestern portions. [30] Southern Africa receives most of its rainfall from summer convective storms, tropical lows, mesoscale convective systems. Extratropical cyclones moving through the Westerlies, can also bring significant winter rainfall. Once a decade, tropical cyclones lead to excessive rainfall across the region. [31]
Snow is an almost annual occurrence on some of the mountains of South Africa, including those of the Cedarberg and around Ceres in the South-Western Cape, and on the Drakensberg in Natal and Lesotho. Tiffendell Resort, in the Drakensberg, is the only commercial ski resort in South Africa, and has "advanced snow-making capability" allowing skiing for three months of the year. [32] The Mountain Club of South Africa (MCSA) and the Mountain and Ski Club (MSC) [33] of the University of Cape Town both have equipped ski huts in the Hex River mountains. Skiing including snowboarding in the Cape is a hit-and-miss affair, both in terms of timing of snowfalls, and whether there is sufficient snow to cover the rocks.
Table Mountain gets a light dusting of snow on the Front Table and also at Devil's Peak every few years. Snowfalls on Table Mountain took place on 20 September 2013; [34] 30 August 2013; [35] 5 August 2011; [36] and on 15 June 2010. [37]
Snow is a rare occurrence in Johannesburg; it fell in May 1956, August 1962, June 1964, September 1981, August 2006, and on 27 June 2007, [38] accumulating up to 10 centimetres (3.9 in) in the southern suburbs.
Additionally, snow regularly falls in the Atlas Mountains in the Maghreb, as well as the Mediterranean regions and Sinai peninsula of Egypt. Snowfall is also a regular occurrence at Mount Kenya and Mount Kilimanjaro in Tanzania.
There have been permanent glaciers on the Rwenzori Mountains, on the border of Uganda and the Democratic Republic of the Congo. However, by the 2010s, the glaciers were in retreat, and they are under threat of disappearing through rising temperatures. [39]
Climate change in Africa is an increasingly serious threat as Africa is among the most vulnerable continents to the effects of climate change. [40] [41] [42] Some sources even classify Africa as "the most vulnerable continent on Earth". [43] [44] Climate change and climate variability will likely reduce agricultural production, food security and water security. [45] As a result, there will be negative consequences on people's lives and sustainable development in Africa. [41]
Over the coming decades, warming from climate change is expected across almost all the Earth's surface, and global mean rainfall will increase. [46] Currently, Africa is warming faster than the rest of the world on average. Large portions of the continent may become uninhabitable as a result of the rapid effects of climate change, which would have disastrous effects on human health, food security, and poverty. [47] [48] [49] Regional effects on rainfall in the tropics are expected to be much more spatially variable. The direction of change at any one location is often less certain.
Observed surface temperatures have generally increased by about 1 °C in Africa since the late 19th century to the early 21st century. [50] In the Sahel, the increase has been as much as 3 °C for the minimum temperature at the end of the dry season. [50] Data for temperature and rainfall shows discrepancies from the norm, both in timing and location. [51] [41] [52]
For instance, Kenya has a high vulnerability to the impacts of climate change. The main climate hazards include droughts and floods as rainfall will likely become more intense and less predictable. Climate models predict that temperatures will rise by 0.5 to 2 °C. [53] In the informal urban settlements of Nairobi the urban heat island effect adds to the problem as it creates even warmer ambient temperatures. This is due to home construction materials, lack of ventilation, sparse green space, and poor access to electrical power and other services. [54]
The African Union has put forward 47 goals and corresponding actions in a 2014 draft report to combat and mitigate climate change in Africa. [55] The International Monetary Fund suggested in 2021 that $50 billion might be necessary to cover the costs of climate change adaptation in Africa. [56] [57] [58]In chapter 9 of the IPCC Sixth Assessment Report, it is reported that although greenhouse gas emissions are among the lowest in Africa, anthropogenic climate change has severely threatened daily life. People experience extreme food insecurity, high mortality rates, major biodiversity loss, and more as a result of global warming. Additionally, because of reduced economic activity and growth and inequities in funding, the ability for adaptation to these conditions is also reduced. [59]
Tornadoes can occur regularly in South Africa along the eastern coast with the Indian Ocean. [60]
Powerful tropical cyclones regularly affect southeastern Africa. On average, 1.5 tropical cyclones strike Madagascar each year, which is the most affected area in Africa. [61] In March 1927, a tropical cyclone struck eastern Madagascar, killing at least 500 people. [62] In March 2004, Cyclone Gafilo hit northeastern Madagascar as one of the island's strongest ever cyclones, killing 363 people, leaving US$250 million in damage. [63] [64] In March 2019, Cyclone Idai hit central Mozambique and killed 1,302 people across Southern Africa, – affecting more than 3 million people. Total damages from Idai across Mozambique, Zimbabwe, Madagascar, and Malawi were estimated to be at least $2.2 billion (2019 USD). [65] [66] Roughly one month later, Cyclone Kenneth struck northern Mozambique as the country's strongest ever landfall. [67] In 2020, Cyclone Freddy struck Mozambique in two different locations, producing widespread rainfall that killed 1,434 people along its path, mostly in Malawi. [68] [69]
Occasionally, cyclones in the Mediterranean can affect northern Africa, and which also have characteristics of a tropical cyclone. In September 2023, Storm Daniel moved ashore Libya and produced heavy rainfall, producing flash flooding after two dams failed. The storm killed at least 4,333 people in the country, becoming the deadliest storm to hit Africa in recorded history. [70] [71] In September 1969, a cyclone in the Mediterranean Sea killed nearly 600 people in Tunisia and Libya. [72] Cyclones from the Indian Ocean can strike the Horn of Africa. In November 2013, a deep depression struck Somalia and killed 162 people while also causing extensive livestock damage. [73] [74] [75] The temperature contrast between the hot Sahara Desert in northern Africa and the cooler Gulf of Guinea to the south produces the African easterly jet, which generates tropical waves, or an elongated area of low pressure. These waves are often the formation source of Atlantic and Pacific hurricanes. [76]
Africa's weather forecasting infrastructure is significantly underdeveloped, affecting its ability to manage severe weather events. With a population of approximately 1.2 billion, Africa only has 37 weather radar stations, in stark contrast to the 636 stations in the United States and European Union. This scarcity of weather stations and early warning systems leads to inadequate disaster preparedness and response, compounded by maintenance issues with many existing radar systems. The lack of proper infrastructure results in high fatality rates and extensive damage during disasters. For instance, in 2023, severe flooding and landslides around Lake Kivu resulted in at least 600 deaths, and Cyclone Idai in East Africa caused over 1,000 deaths due to insufficient early warnings. These incidents underscore the urgency of investing in early warning systems, which can significantly reduce damage and save lives. The World Meteorological Organization suggests that an $800 million investment in developing countries could prevent annual losses of $3 to $16 billion. [77]
Mali is a landlocked nation in West Africa, located southwest of Algeria, extending south-west from the southern Sahara Desert through the Sahel to the Sudanian savanna zone. Mali's size is 1,240,192 square kilometers.
Extreme weather includes unexpected, unusual, severe, or unseasonal weather; weather at the extremes of the historical distribution—the range that has been seen in the past. Extreme events are based on a location's recorded weather history. They are defined as lying in the most unusual ten percent. The main types of extreme weather include heat waves, cold waves and heavy precipitation or storm events, such as tropical cyclones. The effects of extreme weather events are economic costs, loss of human lives, droughts, floods, landslides. Severe weather is a particular type of extreme weather which poses risks to life and property.
The climate of Mumbai is tropical, with defined wet and dry seasons. The mean annual temperature is 27.7 °C or 81.9 °F. Average annual rainfall is 2,213.4 millimetres or 87 inches in Colaba, which represents South Mumbai and 2,502.3 millimetres or 99 inches in Santacruz, which represents central and suburban Mumbai. The mean maximum average temperatures is about 32 °C (90 °F) in summer and 30 °C (86 °F) in winter, while the average minimums are 26 °C (79 °F) in summer and 18 °C (64 °F) in winter. The city experiences a lengthy, practically rainless dry season, and a relatively short, but extremely rainy wet season; due to the Southwest Monsoon and orographic influences from the nearby Western Ghats.
The climate of India consists of a wide range of weather conditions across a vast geographic scale and varied topography. Based on the Köppen system, India hosts six major climatic sub types, ranging from arid deserts in the west, alpine tundra and glaciers in the north, and humid tropical regions supporting rain forests in the southwest and the island territories. Many regions have starkly different microclimates, making it one of the most climatically diverse countries in the world. The country's meteorological department follows the international standard of four seasons with some local adjustments: winter, summer, monsoon or rainy season, and a post-monsoon period.
This is a list of meteorology topics. The terms relate to meteorology, the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting.
The climate of Puerto Rico in the Köppen climate classification is predominantly tropical rainforest. Temperatures throughout the year are warm to hot, averaging near 85 °F (29 °C) in lower elevations and 70 °F (21 °C) in the mountains. Easterly trade winds pass across the island year round while the rainy season stretches from April into November. The relatively cool trade winds are blocked by the mountains of the Cordillera Central which causes rain shadows and sharp variations in the temperature and wind speed over short distances. About a quarter of the average annual rainfall for Puerto Rico occurs during tropical cyclones, which are more frequent during La Niña years.
The characteristics of United States rainfall climatology differ significantly across the United States and those under United States sovereignty. Summer and early fall bring brief, but frequent thundershowers and tropical cyclones which create a wet summer and drier winter in the eastern Gulf and lower East Coast. During the winter, and spring, Pacific storm systems bring Hawaii and the western United States most of their precipitation. Low pressure systems moving up the East Coast and through the Great Lakes, bring cold season precipitation to from the Midwest to New England, as well as Great Salt Lake. The snow to liquid ratio across the contiguous United States averages 13:1, meaning 13 inches (330 mm) of snow melts down to 1 inch (25 mm) of water.
Australia's climate is governed mostly by its size and by the hot, sinking air of the subtropical high pressure belt. This moves north-west and north-east with the seasons. The climate is variable, with frequent droughts lasting several seasons, thought to be caused in part by the El Niño-Southern Oscillation. Australia has a wide variety of climates due to its large geographical size. The largest part of Australia is desert or semi-arid. Only the south-east and south-west corners have a temperate climate and moderately fertile soil. The northern part of the country has a tropical climate, varying between grasslands and desert. Australia holds many heat-related records: the continent has the hottest extended region year-round, the areas with the hottest summer climate, and the highest sunshine duration.
The climate of the north and central parts of the U.S. state of Florida is humid subtropical. South Florida has a tropical climate. There is a defined rainy season from May through October when air mass thundershowers that build in the heat of the day drop heavy but brief summer rainfall.
Texas' weather varies widely, from arid in the west to humid in the east. The huge expanse of Texas encompasses several regions with distinctly different climates: Northern Plains, Trans-Pecos Region, Texas Hill Country, Piney Woods, and South Texas. Generally speaking, the part of Texas that lies to the east of Interstate 35 is subtropical, while the portion that lies to the west of Interstate 35 is arid desert.
The climate of Georgia is a humid subtropical climate, with most of the state having short, mild winters and long, hot summers. The Atlantic Ocean on the east coast of Georgia and the hill country in the north impact the state's climate. Also, the Chattahoochee River divides Georgia into separate climatic regions with the mountain region to the northwest being cooler than the rest of the state; the average temperatures for the mountain region in January and July are 39 °F (4 °C) and 78 °F (26 °C) respectively. Winter in Georgia is characterized by mild temperatures and little snowfall around the state, with the potential for snow and ice increasing in the northern parts of the state. Summer daytime temperatures in Georgia often exceed 95 °F (35 °C). The state experiences widespread precipitation. Tornadoes and tropical cyclones are common.
The climate of the United States varies due to changes in latitude, and a range of geographic features, including mountains and deserts. Generally, on the mainland, the climate of the U.S. becomes warmer the further south one travels, and drier the further west, until one reaches the West Coast.
North Carolina's climate is varying, from the Atlantic coast in the east to the Appalachian Mountain range in the west. The mountains often act as a "shield", blocking low temperatures and storms from the Midwest from entering the Piedmont and Coastal Plain of North Carolina.
South Carolina has a humid subtropical climate, with hot summers throughout most of the state. But, an exception does occur in the Blue Ridge Mountains, as outlier pockets of an Oceanic Climate do exist. Mild winters predominate in the eastern and southern part of the state, but cool to occasionally cold winters are the standard in the northwestern area of the state, especially areas at or above 600 feet in elevation. On average, between 40 and 80 inches of precipitation falls annually across the state, potentially even in excess of 100 inches in portions of the Appalachian temperate rainforest. Tropical cyclones, and afternoon thunderstorms due to hot and humid conditions, contribute to precipitation during the summer and sometimes fall months, while extratropical cyclones contribute to precipitation during the fall, winter, and spring months. The coast experiences nearly all of their tropical weather impacts from storms coming directly from the Atlantic coast. The northwestern area of the state can receive impacts from both Atlantic basin storms moving westward from the coast and also occasionally very heavy rainfall and flooding from storms originating from the Gulf of Mexico that move inland towards the northeast after making landfall from the Florida Panhandle to Louisiana.
Pakistan's climate varies from a continental type of climate in the north (Gilgit-Baltistan,Kashmir,KPK), a mountainous dry climate in the west (Baluchistan), a wet climate in the East (Punjab) an arid climate in the Thar Desert, to a tropical climate in the southeast (Sindh), characterized by extreme variations in temperature, both seasonally and daily, because it is located on a great landmass barely north of the Tropic of Cancer.
Earth rainfall climatology Is the study of rainfall, a sub-field of meteorology. Formally, a wider study includes water falling as ice crystals, i.e. hail, sleet, snow. The aim of rainfall climatology is to measure, understand and predict rain distribution across different regions of planet Earth, a factor of air pressure, humidity, topography, cloud type and raindrop size, via direct measurement and remote sensing data acquisition. Current technologies accurately predict rainfall 3–4 days in advance using numerical weather prediction. Geostationary orbiting satellites gather IR and visual wavelength data to measure realtime localised rainfall by estimating cloud albedo, water content, and the corresponding probability of rain.
Europe is generally characterized by a temperate climate. Most of Western Europe has an Oceanic climate, in the Köppen climate classification, featuring cool to warm summers and cool winters with frequent overcast skies. Southern Europe has a distinctively Mediterranean climate, which features warm to hot, dry summers and cool to mild winters and frequent sunny skies. Central-eastern Europe is classified as having a humid continental climate, which features warm to hot summers and cold winters.
Climate change affect tropical cyclones in a variety of ways: an intensification of rainfall and wind speed, an increase in the frequency of very intense storms and a poleward extension of where the cyclones reach maximum intensity are among the consequences of human-induced climate change. Tropical cyclones use warm, moist air as their source of energy or fuel. As climate change is warming ocean temperatures, there is potentially more of this fuel available.
The climate of Asia is dry across its southwestern region. Some of the largest daily temperature ranges on Earth occur in the western part of Asia. The monsoon circulation dominates across the southern and eastern regions, due to the Himalayas forcing the formation of a thermal low which draws in moisture during the summer. The southwestern region of the continent experiences low relief as a result of the subtropical high pressure belt; they are hot in summer, warm to cool in winter, and may snow at higher altitudes. Siberia is one of the coldest places in the Northern Hemisphere, and can act as a source of arctic air mass for North America. The most active place on Earth for tropical cyclone activity lies northeast of the Philippines and south of Japan, and the phase of the El Nino-Southern Oscillation modulates where in Asia landfall is more likely to occur. Many parts of Asia are being impacted by climate change.
Climate change in Africa is an increasingly serious threat as Africa is among the most vulnerable continents to the effects of climate change. Some sources even classify Africa as "the most vulnerable continent on Earth". Climate change and climate variability will likely reduce agricultural production, food security and water security. As a result, there will be negative consequences on people's lives and sustainable development in Africa.