A heat wave or heatwave, sometimes described as extreme heat, is a period of abnormally hot weather. Definitions vary but are similar. A heat wave is usually measured relative to the usual climate in the area and to normal temperatures for the season. Temperatures that humans from a hotter climate consider normal, can be regarded as a heat wave in a cooler area. This would be the case if the warm temperatures are outside the normal climate pattern for that area. High humidity often occurs during heat waves as well. This is especially the case in oceanic climate countries. Heat waves have become more frequent, and more intense over land, across almost every area on Earth since the 1950s, the increase in frequency and duration being caused by climate change.
The July 1995 Chicago heat wave led to 739 heat-related deaths in Chicago over a period of five days. Most of the victims of the heat wave were elderly poor residents of the city, who did not have air conditioning, or had air conditioning but could not afford to turn it on, and did not open windows or sleep outside for fear of crime. The heat wave also heavily impacted the wider Midwestern region, with additional deaths in both St. Louis, Missouri and Milwaukee, Wisconsin.
The 1980 United States heat wave was a period of intense heat and drought that wreaked havoc on much of the Midwestern United States and Southern Plains throughout the summer of 1980. It was among the most destructive and deadliest natural disasters in U.S. history, claiming at least 1,700 lives. Because of the massive drought, agricultural damage reached US$20 billion. It is among the billion-dollar weather disasters listed by the National Oceanic and Atmospheric Administration.
The Summer 2006 North American heat wave was a severe heat wave that affected most of the United States and Canada, killing at least 225 people and bringing extreme heat to many locations. At least three died in Philadelphia, Arkansas, and Indiana. In Maryland, the state health officials reported that three people died of heat-related causes. Another heat related death was suspected in Chicago.
The 2006 European heat wave was a period of exceptionally hot weather that arrived at the end of June 2006 in certain European countries. The United Kingdom, France, Belgium, the Netherlands, Luxembourg, Italy, Poland, the Czech Republic, Hungary, Germany and western parts of Russia were most affected.
The 1936 North American heat wave was one of the most severe heat waves in the modern history of North America. It took place in the middle of the Great Depression and Dust Bowl of the 1930s and caused more than 5,000 deaths. Many state and city record high temperatures set during the 1936 heat wave stood until the 2012 North American heat wave. Many more endure to this day; as of 2022, 13 state record high temperatures were set in 1936. The 1936 heat wave followed one of the coldest winters on record.
North Dakota's climate is typical of a continental climate with cold winters and warm-hot summers. The state's location in the Upper Midwest allows it to experience some of the widest variety of weather in the United States, and each of the four seasons has its own distinct characteristics. The eastern half of the state has a humid continental climate with warm to hot, somewhat humid summers and cold, windy winters, while the western half has a semi-arid climate with less precipitation and less humidity but similar temperature profiles. The areas east of the Missouri River get slightly colder winters, while those west of the stream get higher summer daytime temperatures. In general, the diurnal temperature difference is prone to be more significant in the west due to higher elevation and less humidity.
The state of Alabama is classified as humid subtropical (Cfa) under the Köppen climate classification. The state's average annual temperature is 64 °F (18 °C). Temperatures tend to be warmer in the state's southern portion with its proximity to the Gulf of Mexico, while its northern portions, especially in the Appalachian Mountains in the northeast, tend to be slightly cooler. Alabama generally has hot, humid summers and mild winters with copious precipitation throughout the year. The state receives an average of 56 inches (1,400 mm) of rainfall each year and experiences a lengthy growing season of up to 300 days in its southern portion. Hailstorms occur occasionally during the spring and summer here, but they are seldom destructive. Heavy fogs are rare, and they are confined chiefly to the coast. Thunderstorms also occur year-around. They are most common in the summer, but they are most commonly severe during the spring and late autumn. That is when destructive winds and tornadoes occur frequently, especially in the northern and central parts of the state. Central and northern Alabama are squarely within Dixie Alley, the primary area in the U.S. outside the Southern Plains with relatively high tornado risk. Alabama is ranked second in the U.S for the deadliest tornadoes. Hurricanes are quite common in the state, especially in the southern part. Major hurricanes occasionally strike the coast, such as Hurricane Frederic in September 1979 and Hurricane Ivan in September 2004; both storms resulted in significant to devastating damage in the Mobile area.
The 2010 Northern Hemisphere summer heat waves included severe heat waves that impacted most of the United States, Kazakhstan, Mongolia, China, Hong Kong, North Africa and the European continent as a whole, along with parts of Canada, Russia, Indochina, South Korea and Japan during July 29, 2010. The first phase of the global heatwaves was caused by a moderate El Niño event, which lasted from June 2009 to May 2010. This lasted only from April 2010 to June 2010 and caused only moderate above-average temperatures in the affected regions, but it also set new record high temperatures for most of the area affected in the Northern Hemisphere.
The 2011 North American heat wave was a deadly summer 2011 heat wave that affected the Southern Plains, the Midwestern United States, Eastern Canada, the Northeastern United States, and much of the Eastern Seaboard, and had Heat index/Humidex readings reaching upwards of 131 °F (55 °C). On a national basis, the heat wave was the hottest in 75 years.
In March 2012, one of the greatest heat waves was observed in many regions of North America. Very warm air pushed northward west of the Great Lakes region, and subsequently spread eastward. The intense poleward air mass movement was propelled by an unusually intense low level southerly jet that stretched from Louisiana to western Wisconsin. Once this warm surge inundated the area, a remarkably prolonged period of record setting temperatures ensued.
The Summer 2012 North American heat wave was one of the most severe heat waves in modern North American history. It resulted in more than 82 heat-related deaths across the United States and Canada, and an additional twenty-two people died in the resultant June 2012 North American derecho. This long-lived, straight-line wind and its thunderstorms cut electrical power to 3.7 million customers. Over 500,000 were still without power on July 6, as the heat wave continued. Temperatures generally decreased somewhat the week of July 9 in the east, but the high pressure shifted to the west, causing the core of the hot weather to build in the Mountain States and the Southwestern United States shifting eastwards again by mid-July. By early August, the core of the heat remained over the Southern Plains.
The 2006–08 Southeastern United States drought was a crippling drought that struck the southeast of the U.S. Several reasons, including an unusually strong Bermuda high pressure and La Niña in the eastern Pacific Ocean were responsible for the drought. 2007 was particularly dry across the region, with rivers and lakes dropping to record-low levels.
The 2017–18 North American winter saw weather patterns across North America that were very active, erratic, and protracted, especially near the end of the season, resulting in widespread snow and cold across the continent during the winter. Significant events included rare snowfall in the South, an outbreak of frigid temperatures that affected the United States during the final week of 2017 and early weeks of January, and a series of strong nor'easters that affected the Northeastern United States during the month of March. In addition, flooding also took place during the month of February in the Central United States. Finally the winter came to a conclusion with a powerful storm system that caused a tornado outbreak and blizzard in mid-April. The most intense event, however, was an extremely powerful cyclonic blizzard that impacted the Northeastern United States in the first week of 2018. Similar to the previous winter, a La Niña was expected to influence the winter weather across North America.
The 2018 Britain and Ireland heatwave was a period of unusually hot weather that took place in June, July and August. It caused widespread drought, hosepipe bans, crop failures, and a number of wildfires. These wildfires worst affected northern moorland areas around the Greater Manchester region, the largest was at Saddleworth Moor and another was at Winter Hill, together these burned over 14 square miles (36 km2) of land over a period of nearly a month.
The 2018 European drought and heat wave was a period of unusually hot weather that led to record-breaking temperatures and wildfires in many parts of Europe during the spring and summer of 2018. It is part of a larger heat wave affecting the northern hemisphere, caused in part by the jet stream being weaker than usual, allowing hot high-pressure air to linger in the same place. According to the European Drought Observatory, most of the areas affected by drought are across northern and central Europe. According to the World Meteorological Organization, the severe heat waves across the northern hemisphere in the summer of 2018, are linked to climate change in Europe, as well as events of extreme precipitation.
The 2021 Western North America heat wave was an extreme heat wave that affected much of Western North America from late June through mid-July 2021. The heat wave affected Northern California, Idaho, Western Nevada, Oregon, and Washington in the United States, as well as British Columbia, and in its latter phase, Alberta, Manitoba, the Northwest Territories, Saskatchewan, and Yukon, all in Canada. It also affected inland regions of Central and Southern California, Nevada, and Montana, though the temperature anomalies were not as extreme as in the regions farther north.
The following is a list of weather events that occurred on Earth in the year 2022. The year began with a La Niña. There were several natural disasters around the world from various types of weather, including blizzards, cold waves, droughts, heat waves, wildfires, floods, tornadoes, and tropical cyclones. The deadliest weather event of the year were the European heat waves, which killed over 26,000 people, 11,000 of which were in France. The costliest weather event of the year was Hurricane Ian, which caused at least $112.9 billion in damages in Florida and Cuba. Another significant weather event was the Pakistan floods, which killed 1,739 people and a total of $14.9 billion in damages.
From late spring to late summer heat waves in 2022 smashed many records in North America between May and September of that year. Dozens of temperature records were surpassed in the United States.
