Heat wave

Not to be confused with heat burst.
For the disease that is produced by heat, see Heat stroke.
"Heat waves" redirects here. For the Glass Animals song, see Heat Waves. For other uses, see Heat wave (disambiguation).

A high pressure system in the upper atmosphere traps heat near the ground, forming a heat wave (for North America in this example)

A heat wave[1] or heatwave,[2] sometimes described as extreme heat, is a period of abnormally hot weather, usually more than 5 days.[3]: 2911  Definitions vary but are similar.[4] A heat wave is usually measured relative to the usual climate in the area and to normal temperatures for the season.[3]: 2911  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.[5] 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.[6][7]

Heat waves form when a high-pressure area in the upper atmosphere strengthens and remains over a region for several days up to several weeks.[8] This traps heat near the earth's surface. It is usually possible to forecast heat waves, thus allowing the authorities to issue a warning in advance.

Heat waves have an impact on the economy. They can reduce labour productivity, disrupt agricultural and industrial processes and damage infrastructure.[9][10] Severe heat waves have caused catastrophic crop failures and thousands of deaths from hyperthermia. They have increased the risk of wildfires in areas with drought. They can lead to widespread electricity outages because more air conditioning is used. A heat wave counts as extreme weather. It poses danger to human health, because heat and sunlight overwhelm the thermoregulation in humans.

  1. ^ "Heatwave – noun – Definition". Merriam-Webster.
  2. ^ "Heatwave – noun – Definition". gcunoxfohoarnersdictionaries.com.
  3. ^ a b Cite error: The named reference :42 was invoked but never defined (see the help page).
  4. ^ Meehl, G. A (2004). "More Intense, More Frequent, and Longer Lasting Heat Waves in the 21st Century". Science. 305 (5686): 994–997. Bibcode:2004Sci...305..994M. doi:10.1126/science.1098704. PMID 15310900.
  5. ^ Robinson, Peter J (2001). "On the Definition of a Heat Wave". Journal of Applied Meteorology. 40 (4): 762–775. Bibcode:2001JApMe..40..762R. doi:10.1175/1520-0450(2001)040<0762:OTDOAH>2.0.CO;2.
  6. ^ Climate Change 2021: The Physical Science Basis. Intergovernmental Panel on Climate Change. 2021. pp. 8–10.
  7. ^ Thompson, Andrea, "This Summer’s Record-Breaking Heat Waves Would Not Have Happened without Climate Change", Scientific American 25 July 2023
  8. ^ Cite error: The named reference :1 was invoked but never defined (see the help page).
  9. ^ Bottollier-Depois, Amélie. "Deadly heatwaves threaten economies too". phys.org. Retrieved 15 July 2022.
  10. ^ García-León, David; Casanueva, Ana; Standardi, Gabriele; Burgstall, Annkatrin; Flouris, Andreas D.; Nybo, Lars (4 October 2021). "Current and projected regional economic impacts of heatwaves in Europe". Nature Communications. 12 (1): 5807. Bibcode:2021NatCo..12.5807G. doi:10.1038/s41467-021-26050-z. ISSN 2041-1723. PMC 8490455. PMID 34608159.