Air Temperature
During the first two decades of August, abnormally hot weather persisted all over the European Territory of Russia. Unprecedented maxima of air temperatures were recorded in the Volga Region, Bashkiria, Cis-Urals and southern Urals, with the thermometer readings reaching +35…40° and remaining as high as that for several days in a row. To some extent, the heat subsided not earlier than in the third decade, and solely in the North-Western Federal District and the north of the Central one to end up with normal decade-averaged temperatures, and with frosts on some days in the Murmansk and Arkhangelsk Regions as well as in the Karelia and Komi Republics. But the weather in the Southern, North Caucasian, Volga and Ural Federal Districts remained hot until the end of the month, culminating in high temperatures never observed before in a number of regions. In the outcome, the average temperature of August in the ETR became the fifth highest since the beginning of regular meteorological observations in 1891: the third highest after 2010 and 2007 in the Southern Federal District and the second highest after 2016 in the Volga Federal District.
The temperatures in the Asian Territory of Russia fluctuated more sharply. In Kolyma and Chukotka, autumn frosts occurred as early as in the first decade, and the decade-averaged temperatures were sub-normal. New daily minima were recorded along the Sea of Okhotsk in the Khabarovsk Territory. Cold air broke through to the outermost eastern Russian regions and the north of Siberia on some other days of August as well, but the air temperature in Siberia and in the Far East was higher than normal for most of the month. This was especially true for the south of Western Siberia (the Altai Territory and the Omsk and Tomsk Regions), Yakutia and the Far East (the Khabarovsk Territory and the Amur, Sakhalin and Magadan Regions) where the air temperature reached +30-35° in some places. New daily temperature maxima were recorded multiple times. At the end of summer, the air temperature in the Khanty-Mansi Autonomous District exceeded +30° for the first time in history. The monthly-averaged air temperature in the Asian Territory was the second highest after the record-breaking hot August 1995.
Regarding Russia as a whole, this August was the hottest in the history of meteorological observations, surpassing the previous achievement of 2016. The monthly-averaged temperature was higher than normal almost everywhere save for the north-east and for parts of the Sakhalin and Kuril islands: by 2° or more in most of the country, and by 4-5° or more in the south of the ETR and of the Urals, in the Volga region and in Taimyr.
The average temperature of summer 2021 reproduced the record-breaking value of 2016 both for the entire territory of Russia and for its Asian Territory alone; in the ETR, this summer was the second hottest in the meteorological chronicle, yielding precedence to the fantastic heat of summer 2010 only. It was the hottest in the North-Western and Far Eastern Federal Districts, the second hottest in the Southern, North Caucasian and Volga ones, and the third hottest in the Central Federal District. The summer temperatures were above-normal throughout the entire territory of Russia excluding Chukotka: the anomalies were 2-3 or more degrees in the ETR, in Yakutia, in the Far East and in the Kara Sea area, and less than 1° in the south-east of the Urals and in the south-west of Siberia only.
In the countries of East and South-East Asia as well as in India, the monthly-averaged temperatures were about normal. They exceeded the normal values by some 2° in certain locations of Mongolia, Japan, Vietnam and India only.
The weather in Central Asia was very hot: the monthly-averaged figures were 2-4 or more degrees higher than normal in many regions, or 5-6° higher in the west of Kazakhstan.
The situation was similar in the Near and Middle East. This August in Iran, Kuwait, Jordan, Israel and in the countries of the Arabian Peninsula was 2-4 or more degrees hotter than usual. In Saudi Arabia, the temperature reached +47° sometimes.
In North Africa, the normal values in the countries of the Mediterranean coast were also exceeded by about 2-4°. There, the air would heat up to +45-50°. New daily temperature maxima were recorded in Algeria, Tunisia and Morocco. This August was the second hottest in the history of North Africa: its average temperature was lower than in August 2015 only.
The south and east of Europe were occupied by heat in August. The anomalies of monthly-averaged temperature in these regions were 2-3° or higher. Yet another wave of summer heat swept across the continent in the middle of the month, and the temperature reached +40-45° in the south of Italy, in Malta, Greece and Spain, and in a number of the Balkan countries. A new absolute temperature maximum of +48.8° for the continent was recorded in Sicily. Temperature maxima were established in manly locations of France and of Spain including Madrid. An all-time maximum of +29.4° was achieved in Iceland.
In most of the USA and Canada, the average temperature in August was close to normal, but on a positive background still. The values 2-3 or more degrees higher than the normal ones were only observed in the north-east of the USA, along its Pacific coast, and in the east of Canada – most remarkably, in its Arctic zone comprising the southern part of Greenland. In the USA, this August was the hottest in the meteorological annals of the south-eastern states, and the fifth hottest for the country as a whole. The monthly-averaged temperature in the north of Mexico was about 2° higher than normal.
As for the entire Northern Hemisphere, the average temperature in August regained (to an accuracy of 0.1°C) the record-breaking value first set in 2016 and then repeated twice: in 2019 and in 2020.
The whole summer in the Northern Hemisphere was also so hot as to reproduce (to an accuracy of 0.1°C) the unprecedented temperatures observed a year before. In terms of seasonal averages, the normal figures were exceeded by 2-3° in most of Europe, in the north of Africa, in the Near and Middle East, in Central Asia, in the north of the US and in the south of Canada. This summer was colder than usual in India, in some southern parts of the Arabian Peninsula as well as in the tropical zone of the Atlantic and Pacific Oceans, but turned out to be the hottest one in the history of the US and in North Africa, replicated the record-breaking temperature in China, and entered the Top Three hottest in Europe and the Top Five hottest in Canada.
The average temperature of August in Moscow was +19.5°, implying an anomaly of +3.1°. This is the seventh or eighth highest value since 1891. Summer turned out to be the second hottest in the meteorological chronicle of the capital (alongside 1972). Summer 2010, which was 1.5° warmer still, preserved its title of the ever-hottest summer.
Ocean Surface Temperature
The mean SST anomaly on the Pacific Ocean in the Northern Hemisphere remained at the level of the previous month, but was significantly lower than at the same time of the previous year when it reached the maximum value. High positive anomalies (higher than 1-2°) were observed at subtropical and temperate latitudes.
The mean SST anomaly on the Atlantic Ocean in the Northern Hemisphere was slowly increasing as compared to the values in the previous months. It was 0.1° higher than in June and 0.2° higher than in July. Almost no negative anomalies of mean SST were revealed with the exception of a small water area off the north-western coast of Africa. Anomalies of +1…2° were observed all over the western part of the Ocean along the coasts of the USA, Canada and Greenland. The temperature in the Barents and Kara Seas in the north, as well as in the Mediterranean and Black Seas, was noticeably higher than normal.
In August, rains targeted the northern and southern parts of the ETR, specifically, the North-West Federal District along with the northern regions of the Central one, and the Southern Federal District. The precipitation amounts accumulated there during the month measured from one and a half to four times the normal figure. But in-between, viz., in the south of the Central Federal District, in the Volga Federal District and in most of the North Caucasian one, the totals were twice lower than usual almost everywhere, or even less than 10% of the normal monthly amount in Bashkiria or in the Samara and Astrakhan Regions. In Ufa, this August was the driest one in the history of meteorological observations. In the first decade of the month, rains flooded the north and north-west of the ETR: 106 mm of rainwater fell in Saint-Petersburg for the first eight days given the normal monthly quantity of 81mm, and 28 mm – more than one third of the normal monthly rate – accumulated for a single hour in Vologda. Rains were most intense in the Murmansk, Arkhangelsk, Smolensk, Tver and Yaroslavl Regions where they brought 15 to 30 or more millimetres of daily precipitation. Showers hit the south of the ETR at the same time, and caused harm in the Crimea, the Krasnodar and Stavropol Territories, the Rostov Region and the republics of the North Caucasus at the beginning of the second decade. These showers brought 87 mm of rainwater (twice the normal monthly amount) just for one night in Kerch, 137 mm (three times this amount) for two days in Taman, 178 mm (four times the weekly amount) in Novorossiysk, and 516 mm (comparable to the annual normal figure) in Temryuk. At the end of the decade, showers flooded the Crimea again. In Simferopol, they brought 57 mm of moisture daily, in excess of the normal monthly quantity. Rains in the south of Russia did not stop in the third decade as well: in the Stavropol Territory and in the Karachay-Cherkessia, they added extra 35-50 mm of rainwater per day.
Precipitation was very scarce in the Ural Federal District. Yet, occasional heavy showers did occur in the Khanty-Mansi Autonomous District. Over the vast spaces of Siberia, the monthly precipitation totals were large in some regions (e.g., 1.5 times the normal amount in the Republic of Tyva and in the Taimyr Autonomous District) but sub-normal in the others (e.g., less than 50% of it in the Kemerovo and Irkutsk Regions, in Khakassia and Evenkiya). Heavy rains poured in the Tyumen Region and in Tyva, and a new daily maximum of precipitation was set in Kyzyl where the normal monthly amount was reached in a week. It was snowing in Taimyr.
Precipitation in the Far Eastern Federal District was abundant, especially in the Amur Region, in the south of the Khabarovsk Territory (up to 1.5 times the normal monthly figure) and in the Magadan Region (up to 2.5 times this amount). New daily precipitation maxima were recorded there. Rains, most notably – heavy ones, started at last in Yakutia and ended up in new daily precipitation maxima in Yakutsk, Verkhoyansk and other locations. At the end of August, torrential rains swept across the Amur Region, the Primorye Territory and Sakhalin (up to 30-70 mm per day). Precipitation was close to normal in Primorye, Sakhalin, Buryatia and the Trans-Baikal Territory, but very scarce in Kamchatka and Chukotka.
In the ETR, this summer was overly rainy in the North-Western and Southern Federal Districts, especially in the latter one; there, the precipitation totals for June-August were 1.5-3.0 or more times the normal summer figures. On the other hand, the Volga Federal District and a significant part of the Central one fell short of summer precipitation, quite short in some places. The precipitation amounts in the Urals were normal or increased save for the south of the region. During this summer, the precipitation rates were close to normal in a considerable part of Siberia, and higher than that in Taimyr and Trans-Baikal. Abundant rains poured in the south of the Far East where their totals were normal, or 1.5 and more times greater in certain places.
China received a lot of precipitation in August. The monthly precipitation totals reached the normal value everywhere excluding the autonomous regions of Xinjiang and Inner Mongolia, and where 1.5-3.0 times greater than that over a large area. In the middle of the month, heavy rains brought 80 to 200 mm of precipitation to certain regions in the provinces of Hubei, Anhui, Hunan and Jiangxi. On the twenties days of August, more than 70 mm of rainwater per hour and more than 230 mm per day fell in the province of Shaanxi, flooding the agricultural lands of an area larger than one thousand hectares. The neighbouring province of Henan was also hit by downpours. A lot of rains fell in the southern regions of Japan where the normal precipitation amounts were exceeded by 2-4 times in places. A similar picture was observed in most of Mongolia. The precipitation totals for this summer were either normal or above-normal in most of China, Mongolia, Korea and Japan. The normal amounts in the south of China ware exceeded by 1.5-3.0 times.
The weather in Vietnam, Laos and the north of Thailand was dry for the most of August. Rains fell in Malaysia, Indonesia and the south of Thailand only, contributing a hundred or more millimetres of precipitation per day in places and causing flash floods. In Singapore, more than 100 mm of rainwater fell in a few hours and flooded the streets and roads of this city-state. The normal monthly amounts in some of its places were exceeded by 1.5-2.0 times.
In India, rains were surprisingly rare during this month. They were abundant in the northern and southern regions only where their monthly totals reached the normal amount or exceeded it by 1.5-2.0 or more times in places. Torrential rains in the north flooded the state of Uttar Pradesh and killed more than 400 people. The water in the Ganges rose 2 metres above the hazardous mark, whereas the downpours in the southern state of Assam caused floods that affected tens of thousands of people. In overall, the precipitation totals for this summer were either normal or increased in most of the country: 1.5-3.0 times larger than normal in the south. During this season of rains, the north-western areas as well as neighbouring Pakistan were the only territories to receive less rainfall than usual.
The weather in the Near and Middle East was dry as it should have been, the Black Sea coast of Turkey being the only region attacked by downpours that resulted in powerful floods damaging the houses and roads, and leading to fatalities. As for the whole summer season, rains were lacking in this region, and brought subnormal amounts of rainwater in its significant part. The precipitation totals were normal in the Levant countries only, and much larger in Turkey.
In Central Asia, the weather was just as dry – apart from the rains which caused floods in Afghanistan. And the summer season as a whole was dry as well, e.g., 1 mm of precipitation in Ashgabat, recognised as the minimum value in the entire history of meteorological observations.
In North Africa, plenty of rains fell in the north of Algeria, producing 2-3 or more times the normal precipitation totals in some locations. The precipitation in the countries to the south of Sahara and in the east of the continent was also profuse: there, the total monthly figures were normal or above-normal everywhere from the Atlantic Ocean to the Red Sea. Heavy rains caused flooding in Niger, in particular, in Niamey, the capital of the country. They also affected neighbouring Nigeria where they led to fatalities. The flooding spread to Douala, the capital of Cameroon where 168 mm of precipitation per day was recorded, as well as to Bangui, the capital of the Central African Republic. Heavy downpours took place in Ethiopia and Sudan, causing numerous damages, losses in livestock, and casualties among the population. Floods due to torrential rains covered Ghana.
Heavy rains repeatedly flooded Europe again. At the beginning of the month, they hit Scotland to flood the streets of Glasgow and to disrupt the operation of road and railway services – in amounts of up to 80 mm of rainwater per day. At the same time, Lombardy, the northern province of Italy, was being flooded at a daily rate of 94 mm of precipitation. From the middle to the end of the month, the countries of Central, Eastern and Northern Europe were suffering from rains. Rains hit the western regions of Austria again, bringing more than 50 mm of rainwater in two hours and leading to new floods that destroyed rail tracks and inundated the tourist centre of Innsbruck. In Sweden, more than 100 mm of precipitation fell in two hours and more than 160 mm per day in the centre of the country, amounting to a new daily maximum. Heavy rains in Eastern Europe (Romania, Poland, Lithuania, Latvia, Belarus and Ukraine) brought 20-40 mm of precipitation per day, and hit the Spanish province of Valencia in the last days of the month, resulting in the daily totals as high as 100-150 mm. The normal precipitation amount for August was reached in Central, Eastern and Northern Europe as well as in the east of Spain and in Scotland, and exceeded by 2-3 or more times in some places. In the rest of the continent, the weather was dry. The overall distribution ofq precipitation in summer was similar: normal or increased totals in the centre, north, north-east and east, and less than normal in the southern countries. According to the meteorological service of Belgium, this summer in the country was the rainiest since the beginning of meteorological observations in 1833.
North America got a lot of rains in August. In the USA, the normal monthly precipitation figures were reached everywhere apart from the states of the west coast and the states of Colorado and New-Mexico, or exceeded by two or more times in some places. Heavy rains hit Tennessee, Nebraska and North Carolina in daily amounts greater than 400 mm in certain locations, causing floods and massive destruction. Conversely, the residents of Colorado, Nevada, Utah, Idaho, Oregon, Montana and North Dakota continued to suffer from the most severe draught which seized more than 94% of the total area of these states. In California, almost no precipitation was observed in August. In Canada, rains in normal or above-normal amounts fell mostly in the central part of the country from its US border to the Arctic, but were rare in Ontario, in Quebec and along the west coast. Heavy rains in Mexico and across Central America brought 1.5-2.0 times the normal monthly amounts in places, with up to 40-60 mm of atmospheric moisture accumulated per day. The downpours caused floods in Mexico, El Salvador and Trinidad, and in the north of Venezuela. While in the centre of Greenland, rain was recorded at an altitude of more than three thousand metres for the first time in the history of meteorological observations since 1950 – any precipitation was in the form of snow before that.
The normal rates of summer precipitation were much overridden in Mexico, as well as in the east of the USA and in Alaska, but the seasonal totals in the rest of North America were either normal, or less than that.
In Moscow, this August was rainy. The monthly precipitation total amounted to 108 mm, or 140% of its normal value. Heavy rain on August, 18, brought 19 mm of rainwater in an hour, which is about a quarter of the normal monthly quantity. Some areas of the Moscow Region received even more precipitation, for example, a new daily maximum of 36 mm was recorded in Klin. The total precipitation for summer in the capital was 245 mm, which is normal.