MAIN WEATHER AND CLIMATE TRAITS IN THE NORTHEN HEMISPHERE AS OF FEBRUARY 2021
 
Air Temperature
 
Abnormally warm weather at the end of January in the ETR grew colder with the onset of the last month of winter. At the beginning, cooling spread solely to the North-West Federal District and to the northern regions of the Central one: there, the average air temperature in the first decade became close to normal or a bit lower than that, by some 1.0-1.5°. The weather in the south of the ETR and in the Cis-Urals was still so warm that numerous daily maxima of air temperature were updated at that time. Nevertheless, Arctic colds came there starting from the second decade, and the decade-averaged air temperatures dropped to -4…-13° below their normal values. Frosts reached as low as -35…-50° in the north including the Arkhangelsk and Murmansk Regions and the Komi Republic, and -40° or below in the south of the Urals. On February 22, a temperature of -51.3° was recorded in the Komi Republic: this was the first time since 2017 when the air temperature in Europe decreased below -50°. Unprecedented colds of -30…-35° were observed in the Moscow region. The temperature dropped to -15° in the Crimea, and a powerful fast ice was formed in the Kaliningrad Bay for the first time in the 21st century.
The weather in the Asian Territory of Russia was also gradually cooling. In the first decade, anomalous warmth accompanied by new temperature maxima was still spreading over the south of Siberia (Tomsk, Kemerovo and Novosibirsk Regions, as well as the Krasnoyarsk Territory) and in the Khanty-Mansi Autonomous District. But in the second decade to follow, all the territory from the Urals to Yakutia was occupied by abnormal colds reaching -50…-54° in the North of Siberia and resulting in the anomalies of decade-averaged temperatures as low as -6…-9°. During this interval, the weather remained warm in the south of the Far East only, new daily maxima being recorded in the Khabarovsk and Primorye Territories and on Sakhalin. But in the last third of the month, colds expanded to these areas as well. There, the decade-averaged air temperature was about 2° below normal, compared to 10-14° below that in Siberia. In the outcome, February 2021 turned out to be cold in Russia: the monthly-averaged air temperature was 2-8° below the normal value over a large territory from the western border to Yakutia, and the average temperature in February for Russia as a whole was sub-normal for the first time since 2011. In the North-West, Volga and Ural Federal Districts, this February entered the Top Twenty of coldest ones for 131 years of regular meteorological observations in the country.
Abnormally cold February pulled the whole winter into a cold spell after itself. Form the Volga region to the Pacific, this winter was colder than usual, the figures being 2-4° below normal everywhere from the Urals to Yakutia. Though, the weather was close to normal in part of the ETR owing to the extraordinary warm first half of winter, and was very warm in the Russian Arctic where the anomalies of season-averaged temperature were as high as +4…+8° or even higher. Strong and prolonged colds observed this winter in Russia were especially remarkable against the background of the previous winter 2019/2020 which became the warmest in the history of meteorological observations in the country.
The weather all over East Asia was warm. The normal monthly-averaged air temperatures were exceeded by 4-6° in China and Mongolia, and by 2-4° in Korea and Japan. New daily maxima of air temperature were established. In China, the all-time highest value rose by as much as 5° and went beyond the +25° mark on one of February days. The past month in China became the warmest February in the history of meteorological observations.
In most of South-East Asia, the average air temperature was close to normal with the exception of Philippines were it was 1-2° above the normal value in some places.
The temperature was also approximately normal in most of India, apart from the north of the country where it was 2-4° above the normal value, as in neighbouring Pakistan. For this reason, the past February in India entered the Top Five of warmest in history.
In the Near and Middle East, this February was very warm. The normal monthly-averaged air temperatures were exceeded by 2-4° or more, and new daily temperature maxima were recorded. In Iraq, the absolute maximum temperature for February was updated to +34°.
The month was exceptionally warm in Central Asia. New high temperature maxima were set all over the region. The thermometer readings rose above +20° in Kazakhstan and above 25° in the republics of Central Asia. A new maximum air temperature for February was set at +32° in Uzbekistan. Throughout the entire region, the normal monthly-averaged air temperatures were exceeded by 2-4° and more.
In North Africa, the monthly-averaged air temperature was close to normal everywhere except for individual areas of Algeria where it was 2-3° above the normal value. Thermometers in neighbouring Libya showed negative values at night sometimes.
In Europe, the first half of February was colder than usual. Residents of the UK encountered the coldest night since 1955, as cold as -23°. Frosts reached -8…-12° in the north of France and -19° in the north of Greece. Record-breaking colds were observed in Norway. Bitter colds spread as far as the Canary Islands. In the mountains, thermometers measured -12°. But all this changed in the third decade when heat came to Europe. Numerous daily maxima of air temperature were recorded in Central Europe. The monthly-averaged air temperature was 2-3 or more degrees above the normal value in Spain, in France, and all over the southern Europe; the conditions close to normal were formed in the rest of Europe.
Most of the US and Canada were caught in a cold trap in February. Unprecedented frosts hit the south of the USA. New air temperature minima were set one after the other all the way from the Canadian border to the Gulf of Mexico. The thermometer readings dropped below -35°, or down to -3° off the coast of the Gulf. February 16, 2021, was marked as the coldest day in the history of the USA. An energy crisis arose due to low temperatures. The electrical substations could not cope with the cold weather, oil refineries shut down, airports and other infrastructure facilities were closed. More than 4.5 million residents were left without electricity for several days. An ice cap formed on the top of Niagara Falls, and ice banks grew along the coasts. But the waterfall did not freeze completely: it came to a full stop just once in history on March 29, 1848. The monthly-averaged air temperatures from the north-western regions of Canada to the southern coast of the US were 2-4 or more degrees below the normal value. The weather remained relatively warm along the Atlantic coast only. There, the air temperature was 2-6° higher than normal in Canada. In the USA, February 2021 was in the Top Twenty of coldest in the entire history of meteorological observations, while in the southern territories from Texas to Mississippi and from the Gulf of Mexico to Kansas, in the Top Ten of coldest ones. The air temperature was 2-3 or more degrees higher than normal in Mexico and the Caribbean Islands.
The average temperature in the Northern Hemisphere exceeded the normal value by about 1° in February. This is the 7th-8th highest result among those in the ranking list since 1891.
February concluded the calendar winter in the Northern Hemisphere and promoted it to rank 5-6 of warmest since 1891. A large part of the Hemisphere received more warmth than prescribed by the climate. For instance, this winter was very warm in Canada where the season-averaged temperature regained the record-breaking value set in 2010. Likewise, winter 2020/21 was the second warmest in North Africa, the third warmest in India and the fourth warmest in China. The air temperature was above-normal in the Balkans, the Middle East and the Arctic. Yet, cold weather in Russia and in the South Pacific due to the development of La Niña affected the average temperature in the Hemisphere where the past winter was the coldest one since 2016.
In Moscow, the average temperature in February was -10.5°, with the anomaly of -2.8°. In spite of cold February, the average winter temperature in the capital was slightly higher than normal owing to the first half of winter, namely, by 0.8°.
 
Ocean Surface Temperature
 
The average SST anomaly in both the Pacific and the Atlantic Ocean became weaker by 0.1° but remained at the February level of the previous year. At the equatorial latitudes of the Pacific Ocean, La Niña was still observed, but the SST anomalies decreased. According to some estimates, La Niña will end in spring, and the South Oscillation will return to its neutral phase. The SST was above-normal all over the tropical latitudes from Philippines to America, and sub-normal off the coasts of Russia, South-East Asia and the USA. The latter was most noticeable in the Sea of Okhotsk.
In the Atlantic ocean, high positive anomalies (+1…2° and more) were formed off the coast of Canada, and high negative ones, off the coasts of Europe, and in the Arctic.
 
Precipitation
 
Russia received a lot of precipitation in February. In any Federal District everywhere from the western border to the Pacific Ocean, the normal precipitation rates were exceeded in the majority of the constituent territories. In the Russian North, the amounts of precipitation were sub-normal in the Kaliningrad Region only, and were normal or above-normal elsewhere. All over Central Russia and Volga region, the normal rates were exceeded by 1.5-2.0 or more times. In the south of the ETR, precipitation was scarce in Dagestan alone, whereas the monthly totals in the rest of the territory were 1.5-2.5 times the normal values. In the Urals and in Siberia, the amounts of precipitation were normal or sub-normal in the northern territories, but were 1.5-3.0 times the normal values in all other parts of this vast area. In the Far East, the precipitation rates were less than normal in Chukotka and in the north of Yakutia, and 1.5-3.5 higher than normal in the remaining territory.
In the first decade, heavy snowfalls passed across the north of the ETR, and came to the Volga and Cis-Ural regions to set up new daily maxima of precipitation totals. At the end of the decade, snowfalls hit the Krasnodar Territory and the foothills of the Caucasus. In the second decade, many record-breaking daily highs were established in Central Russia (the Moscow, Smolensk, Kostroma, Ryazan and Kursk Regions). Snowfalls covered the Crimea, the Krasnodar and Stavropol Territories, and Sakhalin at the same time. In Sakhalin, more than 40 mm of daily precipitation in water equivalent were observed in places, and the depth of the snow cover reached 130 cm. Up to 140 mm of atmospheric moisture fell in Sochi in just one week.
The amounts of precipitation were significantly larger than normal in the eastern provinces of China, and were low in the rest of the country as well as in neighbouring Korea and Japan.
In South-East Asia, the monthly precipitation totals were above-normal in certain locations only. Heavy rains in Indonesia and in the Philippines caused severe floods. In some places, more than 200 mm of precipitation fell per day.
The weather in South Asia and in the Middle East was dry. In a number of Middle Eastern countries (Libya, Syria and Israel), heavy snowfalls were recorded, and the snow cover in some places was 15 cm deep.
In Central Asia, the precipitation was normal or increased in the northern regions of Kazakhstan only, and scarce in the rest of the territory. At the end of the month, a heavy snowfall hit Almaty where up to 20 cm of snow accumulated during one night.
In North Africa, the weather was generally dry everywhere excluding Morocco where the precipitation rates were normal along the Atlantic coastline. Snow fell in Libya and in the north-west of Egypt.
The precipitation was scarce in most of Europe. Heavy rains or snowfalls were observed in just a few countries, chiefly, in the first and second decades. During this time, torrential rains hit the north of Germany and the south-west of France, causing river overflows and floods in some areas. Heavy snowfalls and rains came to Belgium, Netherlands and, in large amounts, to Greece where the flooding was very abrupt and unexpected, and claimed the lives of people. Snow inundated Prague, the capital of the Czech Republic, and rains deluged Budapest, the capital of neighbouring Hungary, where about 20 mm of rainwater fell for 12 hours. Floods due to heavy rains took place in Scotland. Record-breaking precipitation was observed in the west of Belarus. In all the countries listed above, the monthly precipitation totals were normal or above-normal. In the rest of the continent, they were less than normal, by 50% in some places.
The amounts of precipitation in Canada were within the normal limits in the Arctic zone, but small in the rest of the country, just like in the US where they were normal or slightly increased in the eastern United States only. A blizzard hit these states at the beginning of the month, and all the territory from Virginia to the Canadian border was drowned in snow. The depth of the snow cover reached 60-80 cm. The aboveground tracks of the NYC subway disappeared under snow: this resulted in a traffic collapse. In the middle of the month, Texas was also hit by a snowstorm.
Considering the overall precipitation figures during this winter, they were basically normal or increased in the European countries, almost everywhere in Russia, in the eastern regions of the US and Canada, as well as in the eastern and central provinces of China. For example, the normal winter amounts of precipitation were exceeded by 1.5-2.0 or more times in France, the Balkans, the south of Siberia, the Caucasus, and certain regions of China and the USA. Winter precipitation was lacking in Africa and Central Asia, in the Near and Middle East, in India and Mongolia, in most of China and North America, and in South-East Asia.
In February, 70 mm of precipitation, i.e., almost twice the normal amount, fell in Moscow. This is the fourth largest total in the ranking list since 1891. This figure is only excelled by February precipitation in 1966, 2002 and 1957. New daily maxima of precipitation were set several times. The snowfall on February 12 and 13 was particularly heavy, and brought 49 mm of snow in two days. The depth of the snow cover in the capital reached 75 cm by the end of the month.
 
Hydrometcentre of Russia