Heat wave
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A heat wave or heatwave, sometimes described as extreme heat, is a period of abnormally hot weather that lasts for multiple days. A heat wave is usually measured relative to the usual climate in the a
A high pressure system in the upper atmosphere traps heat near the ground, forming a heat wave (for North America in this example)
Scorched grass in Greenwich Park, London, England, during a heatwave in August 2022
Heat stroke treatment at Baton Rouge during the 2016 Louisiana floods
The National Weather Service risk categories for NWS HeatRisk
Dog days
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The dog days or dog days of summer are the hot, sultry days of summer. They were historically the period following the heliacal rising of the star system Sirius, which Hellenistic astrology connected
Heat wave
…to hotter temperatures further north each decade. This might be due to better infrastructure, more modern building design and better public awareness. Dog days Cold wave…
Vegetation on Crete dried out by the August heat
A 9th-century astronomical manuscript, including an illustration of the constellation "Canis Major"
"Some Popular Alleviations of the Dog Days in Hotter New-York" in 1904, including children piled into a public fountain "when the 'cop' is not looking".
Orion (right) and Sirius (bottom), as seen from the Hubble Space Telescope