(This article, originally published Tuesday, was updated Wednesday to add all-time heat records at Mount Washington, N.H., and Tbilisi, Georgia set since Monday. On Thursday, the story was updated to include information on heat-related deaths in Canada and extraordinary heat in Siberia. On Friday, it was updated to add the likely all-time heat record in Africa and Southern California.)
From the normally mild summer climes of Ireland, Scotland and Canada to the scorching Middle East to Southern California, numerous locations in the Northern Hemisphere have witnessed their hottest weather ever recorded over the past week.
Large areas of heat pressure or heat domes scattered around the hemisphere led to the sweltering temperatures. The Canadian Broadcasting Corporation reports the heat is to blame for at least 54 deaths in southern Quebec, mostly in and near Montreal, which endured record high temperatures.
In Northern Siberia, along the coast of the Arctic Ocean – where weather observations are scarce – model analyses showed temperatures soaring 40 degrees above normal on July 5, to over 90 degrees. “It is absolutely incredible and really one of the most intense heat events I’ve ever seen for so far north,” wrote meteorologist Nick Humphrey, who offers more detail on this extraordinary high-latitude hot spell on his blog.
On Thursday, Africa likely witnessed its hottest temperature ever reliably measured. Ouargla, Algeria soared to 124.3 degrees (51.3 Celsius). If verified, it would surpass Africa’s previous highest reliable temperature measurement of 123.3 degrees (50.7 Celsius) set July 13, 1961, in Morocco.
No single record, in isolation, can be attributed to global warming. But collectively, these heat records are consistent with the kind of extremes we expect to see increase in a warming world.
Let’s take a tour around the world of the recent hot-weather milestones.
A massive and intense heat dome has consumed the eastern two-thirds of the United States and southeast Canada since late last week. It’s not only been hot but also exceptionally humid. Here are some of the notable all-time records set:
- The University of California Los Angeles set its all-time high-temperature of 111 degrees on July 6, along with several other locations in Southern California.
- Denver tied its all-time high-temperature record of 105 degrees on June 28.
- Mount Washington, N.H., tied its all-time warmest low temperature of 60 degrees on July 2.
- Burlington, Vt., set its all-time warmest low temperature ever recorded of 80 degrees on July 2.
- Montreal recorded its highest temperature in recorded history, dating back 147 years, of 97.9 degrees (36.6 Celsius) on July 2. The city also posted its most extreme midnight combination of heat and humidity.
- Ottawa posted its most extreme combination of heat and humidity on July 1.
Excessive heat torched the British Isles late last week. The stifling heat caused roads and roofs to buckle, the Weather Channel reported, and resulted in multiple all-time record highs:
- In Scotland, Glasgow had its hottest day on record, hitting 89.4 degrees (31.9 Celsius). Previously, it was reported that Scotland set its hottest temperature on record of 91.8 degrees (33.2 Celsius) on June 28 in Motherwell, about 12 miles southeast of Glasgow. However, upon further evaluation, the U.K. Met Office determined the record was invalid due to an artificial heating source near the temperature sensor.
- In Ireland, on June 28, Shannon hit 89.6 degrees (32 Celsius), its all-time record.
- In Northern Ireland,
A large dome of high pressure, or heat dome, has persistently sat on top of Eurasia over the past week, resulting in some extraordinarily hot weather:
- Tbilisi, Georgia: On July 4, the capital city soared to 104.9 degrees (40.5 Celsius), its all-time record.
- Yerevan, Armenia: On July 2, the capital city soared to 107.6 degrees (42 Celsius), a record high for July and tying its record for any month.
- Several locations in southern Russia topped or matched their warmest June temperatures on record on the 28th.
As we reported, Quriyat, Oman, posted the world’s hottest low temperature ever recorded on June 28: 109 degrees (42.6 Celsius).
These various records add to a growing list of heat milestones set over the past 15 months that are part and parcel of a planet that is trending hotter as greenhouse gas concentrations increase because of human activity:
- In April, Pakistan posted the hottest temperature ever observed on Earth during the month of 122.4 degrees (50.2 Celsius).
- Dallas had never hit 90 degrees in November before, but it did so three times in four days in 2017.
- In late October 2017, temperatures soared to 108 degrees in Southern California, the hottest weather on record so late in the season in the entire United States.
- On Sept. 1, 2017, San Francisco hit 106 degrees, smashing its all-time hottest temperature.
- In late July 2017, Shanghai registered its highest temperature in recorded history, 105.6 degrees (40.9 Celsius).
- In mid-July, Spain posted its highest temperature recorded when Cordoba Airport (in the south) hit 116.4 degrees (46.9 Celsius).
- In July 2017, Death Valley, Calif., endured the hottest month recorded on Earth.
- In late June 2017, Ahvaz, Iran, soared to 128.7 degrees Fahrenheit (53.7 Celsius) — that country’s all-time hottest temperature.
- In late May 2017, the western town of Turbat in Pakistan hit 128.3 degrees (53.5 Celsius), tying the all-time highest temperature in that country and the world-record temperature for May, according to Masters.
(Correction: The original version of this post listed Belfast as part of Ireland. It is the capital of Northern Ireland, and this has been updated.)