MAIN WEATHER AND CLIMATE TRAITS IN THE NORTHEN HEMISPHERE AS OF SEPTEMBER 2021
Air Temperature
Abnormally hot summer in the European Territory of Russia gave way to cold autumn in the first days of September. Frosts in the areas from Murmansk to Volgograd came as early as on the fifth of the month, and occurred again and again since then. The average air temperature was 2-3 or more degrees below normal in the first decade. The overall picture remained about the same later on, but the colds were spreading far and wide to occupy almost all Russia by the end of the month, save for the south of the Far East and the Arctic region. The record-breaking colds were observed in the north of the ETR, in the south of the Urals, in the north of West Siberia and in Chukotka. At the end of the month, 20-degree frosts reached Yakutia already, and the cold spells haunting the ETR came to Tyva, Khakassia, to Irkutsk, Chelyabinsk and Kurgan Regions, and to other areas of Russia as well. The Arctic territories and the south of the Far Eastern Federal District were the only regions where new maxima of air temperature were recorded.
As a result, this September became the coldest in the ETR for the past 25 years since 1996, and hence the coldest one in the 21st century. The monthly-averaged air temperature was less than normal all over Russia. Even though the weather in the Asian Territory of Russia was sometimes much colder than usual, it changed to warmth from time to time, and the monthly-averaged air temperature turned out to be close to normal both in the Asian Territory and in Russia as a whole. This temperature was less than normal in all federal districts of the ETR, close to normal in the Urals and Siberian ones as well as in the north of the Far Eastern Federal District, and higher than normal, remarkably higher indeed, in the south of the latter District. The average air temperature of September 2021 in the south of the Far East was at the third place in the list of highest historical values, yielding to September 2020 and September 1959 only.
In the east and south-east of Asia, this month was warmer than usual, notably in China and Mongolia where the monthly-averaged temperatures exceeded their normal values by 2-4° or more. This September was the hottest in the meteorological history of China, with the previous record of 2005 overridden by as much as 0.5°.
MAIN WEATHER AND CLIMATE TRAITS IN THE NORTHEN HEMISPHERE AS OF AUGUST 2021
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.