June 2021 was the fifth-warmest June – and the warmest for Earth’s land areas – since global record-keeping began in 1880, 0.88 degrees Celsius (1.58°F) above the 20th-century average, NOAA’s National Centers for Environmental Information, NCEI, reported July 13. NASA rated the month the third warmest June on record, 1.13 degrees Celsius (2.03°F) above the 1880-1920 period, which is their best estimate of preindustrial temperature.

The relative coolness of June, by recent standards, was partially the result of the lingering effect of a La Niña event in the Eastern Pacific that had dissipated earlier in the year: Its cool waters limited global ocean temperatures to their sixth warmest June on record, while global land areas experienced their warmest June on record. North America and Africa had their hottest June on record; Europe and Asia had their second hottest June on record.

Figure 1. Departure of temperature from average for June 2021, the fifth-warmest June for the globe since record keeping began in 1880. Record-warm June temperatures were observed across parts of North America, the Atlantic Ocean, Africa, Asia, and northern South America. No record cold was observed. (Image credit: NOAA/NCEI)

January-June ranked as Earth’s eighth warmest such period on record, falling behind 2010 and also the six years of extreme warmth from 2015 to 2020. According to NCEI’s annual temperature outlook, the year 2021 is virtually certain to rank among the 10 warmest years on record, and 95% likely to fall in the range of sixth- to seventh-warmest on record.

Figure 2. National average temperature for the contiguous U.S. in each June going back to 1895. (Image credit: NOAA/NCEI)

June 2021:  record-hot in the U.S.

Unusually intense early-summer heat engulfed most of the contiguous United States in June, leading to the nation’s hottest June on record. The 48-state monthly average of 72.64°F (highs and lows combined) came in 0.88°F above the previous record, set in June 2016, and more than 4°F above the 20th-century average for June (68.59°F). It was even hotter than a typical 20th-century August (72.10°F).

Eight states had their hottest June on record: Arizona, California, Idaho, Nevada, and Utah in the West, and Massachusetts, Rhode Island, and Vermont in New England. Together, these states represent about 19% of the entire U.S. population. The states of Washington and Oregon – which along with southwest Canada experienced one of North America’s deadliest heat waves in years, and perhaps the most extreme heat wave in world history in terms of departure from average – came in with their second hottest June on record, along with Connecticut, Maine, and Montana.

Temperatures were near average across the Deep South, where heavy rains helped tamp down daytime highs. Mississippi had its wettest June on record, and Alabama its fourth wettest, while South Dakota had its driest June on record.

Figure 3. Insurance broker Aon has catalogued 18 billion-dollar weather disasters from January-June 2021.

Four billion-dollar weather disasters in June; 18 so far in 2021

Earth experienced the effects of four billion-dollar weather disasters in June 2021, according to Aon: two severe weather outbreaks in Europe, flooding in China, and drought in Brazil. Through the end of June, Earth had experienced 18 billion-dollar weather disasters, Aon reported, having tabulated a record 50 billion-dollar weather disasters during all of 2020. Below are the details on June’s disasters.

Figure 4. Tornado damage in South Moravia, Czech Republic, on June 24, 2021. (Image credit: South Moravia region Fire and Rescue, via Aon)

June billion-dollar weather disaster #1: Western and central Europe experienced a prolonged period of severe weather June 17-25, with the Czech Republic, Germany, Switzerland and Austria suffering the greatest impacts. The deadliest event was a violent F4 tornado that caused devastating impacts in the South Moravia region of the Czech Republic, killing six people. It was the Czech Republic’s strongest tornado on record. Widespread hail, wind, and flood damage affected many other parts of Europe, with total damage estimated at $4.8 billion.

June billion-dollar weather disaster #2: A severe weather outbreak in central Europe June 28-30 did $1.6 billion in damage and killed one person, with the most notable impacts seen in Switzerland, Germany, Austria, and the Czech Republic. Large hail was the predominant driver of damage, especially in parts of Switzerland and Germany.

June billion-dollar weather disaster #3: Seasonal monsoon rainfall arrived in China in June and extended into early July, with damaging flooding hitting Jiangxi, Anhui, Heilongjiang, and Chongqing. Thousands of structures were inundated, along with more than 160,000 hectares (395,000 acres) of cropland. Total damage was estimated at $1.35 billion.

June billion-dollar weather disaster #4: Drought in Brazil had cost $1.5 billion by the end of June, Aon reported. Government agencies called drought conditions in central and southern Brazil the worst in over 90 years.

Figure 5. A pyrocumulonimbus cloud – a thunderstorm cloud created by the intense heat from a massive wildfire – explodes northwest of Savona, British Columbia, on the evening of June 29, 2021. High winds and temperatures remaining near 40°C at dusk aided extreme fire behavior. (Image credit: Kyle Brittain – The Weather Network)

Deadliest weather disaster of 2021: At least 638 killed in the June western North American heat wave

Aon’s report listed the deadliest weather disaster of the year so far as the intense heat wave that affected southwestern Canada and the northwestern U.S. June 27-29. Government officials in Canada cited that hundreds of heat-related fatalities occurred; likely exceeding 500. The provinces of British Columbia and Alberta reported more than 600 “excess deaths” (fatalities above and beyond what would normally occur in this time frame) during and just after the heat wave. In the U.S., a preliminary total of 138 heat-related fatalities were reported (Oregon: 100, Washington: 38), though this total was likely to rise. Final numbers for the U.S. and Canada will take months to compile.

A rapid-response study from the World Weather Attribution program released on July 7 found that the daily high temperatures observed in a study area encompassing much of western Oregon, Washington, and British Columbia would have been “virtually impossible without human-caused climate change.” The study estimated that the event was roughly a 1-in-1000-year event in today’s climate, but added, “the observed temperatures were so extreme that they lie far outside the range of historically observed temperatures. This makes it hard to quantify with confidence how rare the event was.”

A La Niña Watch is in effect

Neutral conditions were in place during June, NOAA reported in its July 8 monthly discussion of the state of the El Niño/Southern Oscillation, or ENSO. However, the agency issued a La Niña Watch, for the expected arrival of a La Niña event later in the year.

Over the past month, sea surface temperatures in the benchmark Niño 3.4 region of the eastern tropical Pacific (5°N-5°S, 170°W-120°W) were 0.1-0.3 degree Celsius above average. The range for “weak” La Niña conditions is 0.5-1.0 degree Celsius below average.

Forecasters at NOAA and at Columbia University’s International Research Institute for Climate and Society say they expect La Niña conditions to remain “neutral” during the August-September-October period (51% chance). The forecast for the November-December-January period is for a 66% chance of La Niña, 31% chance of ENSO-neutral, and a 3% chance of El Niño. Historically, about half of all winter La Niña events (such as the one during the 2020-2021 winter) have continued into or re-emerged during the following winter.

Figure 6. Departure of sea surface temperature (SST) from average in the benchmark Niño 3.4 region of the eastern tropical Pacific (5°N-5°S, 170°W-120°W). Temperatures were slightly above average over the past month. (Image credit: Tropical Tidbits)

Arctic sea ice: sixth-lowest June extent on record

Arctic sea ice extent during June 2021 was the sixth-lowest in the 43-year satellite record, according to the National Snow and Ice Data Center. However, ice loss accelerated late in the month, and by the first week of July, sea ice extent was tracking at near-record lows for the date.

Antarctic sea ice extent during June was much above average, rising above the 90th percentile by the end of the month.

Notable global heat and cold marks for June 2021

The information below is courtesy of Maximiliano Herrera. Follow him on Twitter: @extremetemps.

– Hottest temperature in the Northern Hemisphere: 53.2°C (127.8°F) at Death Valley, U.S., June 17;
– Coldest temperature in the Northern Hemisphere: -33.4°C (-28.1°F) at Summit, Greenland, June 2;
– Hottest temperature in the Southern Hemisphere: 37.8°C (100.0°F) at Sao Joao do Piaui, Brazil, June 12;
– Coldest temperature in the Southern Hemisphere: -81.4°C (-114.5°F) at Dome Fuji, Antarctica, June 14;
– Highest 2021 average temperature to date (Jan.-Jun.) in the Southern Hemisphere: 29.6°C (85.3°F) at Surabaya Airport, Indonesia; and
– Highest 2021 average temperature to date (Jan.-Jun.) in the Northern Hemisphere: 33.5°C (92.3°F) at Yelimane, Mali.

Major weather stations’ new all-time heat or cold records in June 2021

Among global stations with a record of at least 40 years, 99 set, not just tied, all-time heat records in June (in nations other than Canada). The astonishing heat wave in Canada broke all-time heat records at several hundred stations; these records will be included here once they are tabulated.

Gorgan (Iran) max. 46.3°C, June 2;
Swiehan (United Arab Emirates) max. 51.8°C, June 6;
Temosachic (Mexico) max. 39.4°C, June 11;
Broadus (Montana, U.S.) max. 43.3°C, June 15;
Worland (Wyoming, U.S.) max. 42.8°C, June 16;
Wikieup (Arizona, U.S.) 48.9°C, June 16;
Joba (Oman) max. 51.6°C, June 16: New national record high for Oman;
Richland (Washington, U.S.) max. 44.4°C, June 17;
Tampere (Finland) max. 33.2°C, June 22;
Tampere Airport (Finland) max. 33.0°C, June 22;
Halli (Finland) max. 33.4°C, June 22;
Petrozavodsk (Russia) max. 34.3°C, June 22;
Pinsk (Belarus) max. 36.1°C, June 24;
Corvallis (Oregon, U.S.) max. 43.3°C, June 27;
Eugene (Oregon, U.S.) max. 43.9°C, June 27;
Sexton Summit (Oregon, U.S.) max. 37.8°C, June 27;
Tillamook (Oregon, U.S.) max. 37.8°C, June 27;
Roseburg (Oregon, U.S.) max. 45.6°C, June 27;
Lookout Point Dam (Oregon, U.S.) max. 43.9°C, June 27;
Riddle (Oregon, U.S.) max. 43.9°C, June 27;
Ruch (Oregon, U.S.) max. 44.4°C, June 27;
Leaburg (Oregon, U.S.) max. 45.0°C,  June 27;
Oregon City (Oregon, U.S.) max. 45.6°C, June 27;
Elkton (Oregon, U.S.) max. 46.1°C, June 27;
Lebanon (Oregon, U.S.) max. 48.9°C, June 27: New state record high for Oregon (dubious);
Hoquiam (Washington, U.S.) max. 39.4°C, June 27;
Bremerton (Washington, U.S.) max. 38.9°C, June 27;
Ross Dam (Washington, U.S.) max. 42.2°C, June 27;
Diablo Dam (Washington, U.S.) max. 43.3°C, June 27;
Upper Baker Dam (Washington, U.S.) max. 43.3°C, June 27;
Newhalem (Washington, U.S.) max. 45.0°C, June 28;
Elma (Washington, U.S.) max. 43.3°C, June 28;
Forks (Washington, U.S.) max. 43.3°C, June 28;
Port Townsend (Washington, U.S.) max. 37.8°C, June 28;
Seattle Tacoma AP (Washington, U.S.) max. 42.2°C, June 28;
Olympia (Washington, U.S.) max. 43.3°C, June 28;
Bremerton (Washington, U.S.) max. 43.3°C, June 28;
Shelton (Washington, U.S.) max. 43.3°C, June 28;
Quillayute (Washington, U.S.) max. 43.3°C, June 28;
Port Angeles (Washington, U.S.) max. 37.2°C, June 28;
Bellingham (Washington, U.S.) max. 37.2°C, June 28;
The Dalles (Washington, U.S.) max. 47.8°C, June 28;
Mayfield Power Plant (Washington, U.S.) max. 47.8°C, June 28;
Sol Duc River (Washington, U.S.) max. 47.8°C, June 28;
Clearbrook (Washington, U.S.) max. 41.1°C, June 28;
Kent (Washington, U.S.) max. 41.1°C, June 28;
Skamania (Washington, U.S.) max. 43.9°C, June 28;
Estacada (Oregon, U.S.) max. 47.2°C, June 28;
Hood River (Oregon, U.S.) max. 42.8°C, June 28;
McMinnville (Oregon, U.S.) max. 45.6°C, June 28;
Portland Hillsboro (Oregon, U.S.) max. 45.6°C, June 28;
Portland AP (Oregon, U.S.) max. 46.7°C, June 28;
Troutdale (Oregon, U.S.) max. 46.7°C, June 28;
Salem (Oregon, U.S.) max. 47.2°C, June 28;
Marion Forks (Oregon, U.S.) max. 43.3°C, June 28;
Detroit Dam (Oregon, U.S.) max. 43.9°C, June 28;
Lacomb (Oregon, U.S.) max. 45.0 °C, June 28;
Three Lynx (Oregon, U.S.) max. 45.0°C, June 28;
Foster Dam (Oregon, U.S.) max. 44.4°C, June 28;
Pelton Dam (Oregon, U.S.) max. 48.3°C, June 28:  New State record high for Oregon;
Ashland (Oregon, U.S.) max. 44.4°C, June 28;
Novyj Ushtogan (Kazakhstan) max. 45.4°C, June 28; 
Bend (Oregon, U.S.) max. 42.8°C, June 29;
Hermiston (Oregon, U.S.) max. 47.8°C, June 29;
Joseph (Oregon, U.S.) max. 40.0°C, June 29;
Madras (Oregon, U.S.) max. 45.0°C, June 29;
Redmond (Oregon, U.S.) max. 44.4°C, June 29;
Bonneville Dam (Oregon, U.S.) max. 43.9°C, June 29;
Prineville (Oregon, U.S.) max. 42.8°C, June 29;
Moro (Oregon, U.S.) max. 45.0°C, June 29;
Arlington (Oregon, U.S.) max. 46.1°C, June 29;
Pendleton (Oregon, U.S.) max. 47.8°C, June 29;
Deer Park (Washington, U.S.) max. 43.9°C, June 29;
Winthrop (Washington, U.S.) max. 44.4°C, June 29;
Wenatchee (Washington, U.S.) max. 45.6°C, June 29;
Yakima (Washington, U.S.) max. 45.0°C, June 29;
Ellensburg (Washington, U.S.) max. 45.6°C, June 29;
Omak (Washington, U.S.) max. 47.2°C, June 29;
Walla Walla (Washington, U.S.) max. 46.7°C, June 29;
Ephrata (Washington, U.S.) max. 46.7°C, June 29;
Richland (Washington, U.S.) max. 47.8°C, June 29;
Spokane (Washington, U.S.) max. 45.0°C, June 29;
Stampede Pass (Washington, U.S.) max. 37.2°C, June 29;
Plain (Washington, U.S.) max. 42.8°C, June 29;
Cushman Powerhouse (Washington, U.S.) max. 40.6°C, June 29;
Dayton (Washington, U.S.) max. 43.9°C, June 29;
Republic (Washington, U.S.) max. 42.8°C, June 29;
Mazama (Washington, U.S.) max. 44.4°C, June 29;
Baring (Washington, U.S.) max. 41.7°C, June 29;
Boundary Dam (Washington, U.S.) max. 43.9°C, June 29;
Chelan (Washington, U.S.) max. 43.9°C, June 29;
Goldendale (Washington, U.S.) max. 45.0°C, June 29;
Northport (Washington, U.S.) max. 45.0°C, June 29;
Cougar (Washington, U.S.) max. 44.4°C, June 29;
Whitman Mission (Washington, U.S.) max. 45.6°C, June 29;
Lind (Washington, U.S.) max. 45.6°C, June 29;
Odessa (Washington, U.S.) max. 46.1°C, June 29;
Prosser (Washington, U.S.) max. 45.6°C, June 29;

Four stations set all-time cold records globally in June:
San Jose de Chiquitos (Bolivia) min. -1.0°C, June 30;
Ascension de Guarayos (Bolivia) min. 1.2°C, June 30;
Nueva Asuncion (Paraguay) min. -5.4°C, June 30;  and
Base Aerea Jara (Paraguay) min. -2.8°C, June 30.  

Three all-time national/territorial heat records set or tied in 2021

As of June 30, three nations or territories had set or tied an all-time national heat record in 2021:

United Arab Emirates:  51.8°C (125.2°F) at Swiehan, June 6;
Oman: 51.6°C (124.9°F) at Joba, June 16; and
Canada: 49.6°C (121.3°F) at Lytton, June 29 (record beaten 3 consecutive days).

One all-time national/territorial cold record set or tied in 2021

As of June 30, one nation or territory had set or tied an all-time national cold record in 2021:

United Arab Emirates (for places at low elevations): -2.0°C (28.4°F) at Raknah, January 9.

Fifty-six additional monthly national/territorial heat records beaten or tied as of June 30

In addition to the all-time national heat records listed above (which also count as national monthly records), there have been 56 additional national monthly heat records set so far in 2021:

– January (10): Mexico, Bangladesh, Nigeria, Japan, Malta, Tunisia, Turkey, Russia, Georgia, Spain
– February (12): Iraq, Uzbekistan, Mongolia, South Korea, Liechtenstein, Slovenia, Croatia, Slovakia, Poland, Sweden, Pakistan, Northern Mariana Islands
– March (14): Northern Mariana Islands, Qatar, Saudi Arabia, Bahrain, Kuwait, Pakistan, Oman, Jersey, Guernsey, Germany, Netherlands, Luxembourg, Belgium, US Virgin Islands
– April (4): South Africa, Northern Mariana Islands, Hong Kong, Tajikistan
– May (8): Northern Mariana Islands, Taiwan, Russia, Qatar, Turkmenistan, Uzbekistan, Dominica, Saba
– June (8): Cocos Islands, Congo Brazzaville, Mexico, Belarus, Estonia, Malta, Tunisia, Botswana

Four monthly national/territorial cold records beaten or tied as of June 30

– April (2): Slovenia, Switzerland
– June (2): Saba, Paraguay

Hemispherical and continental temperature records in 2021

– Highest minimum temperature ever recorded in April in the Southern Hemisphere: 31.7°C (89.1°F), at Vioolsdrif, South Africa, April 13.
– Highest minimum temperature ever recorded in May in Europe: 29.4°C (84.9°F), at Zymbragou, Greece, May 2.
– Highest minimum temperature ever recorded in June in North America: 40.3°C (104.5°F), at Stovepipe Wells, U.S., June 18.

Also see: May 2021: Sixth-warmest May on record, NOAA reports

Editor’s note: This post was updated to remove Hungary from the list of nations with a monthly heat record in June.

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Jeff Masters

Jeff Masters, Ph.D., worked as a hurricane scientist with the NOAA Hurricane Hunters from 1986-1990. After a near-fatal flight into category 5 Hurricane Hugo, he left the Hurricane Hunters to pursue a...

Bob Henson

Bob Henson is a meteorologist and journalist based in Boulder, Colorado. He has written on weather and climate for the National Center for Atmospheric Research, Weather Underground, and many freelance...