Air Temperature

In April, fabulous warmth of March survived beyond the Urals only. From the Ural Mountains to Yakutia and Kolyma, the average air temperature in each decade exceeded the normal value by 3-12°. In Siberia, thermometer readings rose to above +20° on some mid-April days, and crossed the +30° mark by the end of the month. This April was the warmest in the history of meteorological observations in Siberia, and the third warmest in the Urals – below April 1995 and April 1951 in the ranking list. The monthly-averaged air temperature in the Far East (in the Primorye and Kamchatka Territories and in the Sakhalin Region) was approximately normal, but it did not preclude this average calculated over the entire Asian territory from regaining its absolute maximum dated 1997.
A strikingly different picture was observed in the ETR where the March heat was replaced by cold. And if the average air temperature in the first decade remained close to normal there or even slightly higher than that in the Central and Volga Regions, the temperature anomalies after a long intervention of cold almost all over the ETR reached -1…-2° in the second decade and -2…-5° in the third one. Night frosts in the south of the ETR could be as severe as -10°. Due to this, the monthly-averaged air temperature was subnormal everywhere from the southern regions of the North-West Federal District to the southern border of Russia. As for the whole country, the European cold was much less powerful yet than the Asian heat, and this April turned out to be the warmest in the meteorological chronicle of Russia. The previous record-breaking achievement of 1997 was exceeded by 0.2°.

In Mongolia and in the northern provinces of China, April was warmer than usual by 5-8° and by 1-2°, respectively. At the same time, the monthly-averaged air temperature in Korea, in Japan and the sough of China was close to normal or less than that.
In Philippines, this month was slightly warmer than usual, and in the rest of South-East Asia, the air temperature was approximately normal.
The air temperature was subnormal in the north and east of India but close to normal in the southern and western provinces of the country. The monthly-averaged temperature in neighbouring Pakistan was 1-2° above the normal value.
In the Near and Middle East, normal temperatures were observed in general. The weather was slightly cooler in the countries of the South Caucasus only; on the contrary, it was warmer than usual in certain regions of Arabia.
In Central Asia, the weather was hot, with the anomalies of the monthly-averaged temperature reaching +2…+5°. Air in the central and eastern regions of Kazakhstan sometimes heated up to +30° or above. New temperature maxima were recorded there, including for two consecutive days in Nur-Sultan, the capital of the country.
In Egypt, April was cold: the monthly-averaged air temperature was 1-2° below the normal value. However, heat reigned in the rest of North Africa where this temperature reached 2-3° above the normal value all over from Algeria in the north to Burkina Faso in the south and occupied the place just below the Top Five of the highest values in the ranking list.
It was very warm in Central and Western Europe. The normal monthly-averaged air temperature was exceeded by 2-4° or more in the areas from the western border of France to the eastern borders of Germany, Austria and the Czech Republic. In France, this April was the third warmest in the history of meteorological observations and in the UK, the fifth warmest one. Yet the weather to the east was cold. In Ukraine, new minima of air temperature were recorded. In Moldova, thermometer readings dropped to -5…-9° causing damages to vineyards and fruit plant fields. Eastern Europe did not keep in step with Western Europe but rather adhered to normal or subnormal monthly-averaged temperatures.
In most of Canada and the USA, April was cold. On the average, the air temperature was 1-3° lower than normal. The only exceptions were observed in the polar regions of Canada and Alaska and along the west coast of the USA: there, the weather was warmer than usual by 2-8° in the north, and by 2-3° in the USA. The weather was extremely hot in Mexico and in the Caribbean where thermometer readings almost reached +40°, and the anomalies of monthly-averaged temperature were +1-3° or higher.
Very warm weather was observed throughout the polar region, with the anomalies equal to +2…+6°. In the Arctic, April 2020 became the warmest in the history of meteorological observations, beating the record of 1995.
The relatively cool weather on the North American continent and in some of the abovementioned regions of the Northern Hemisphere could not restrain the powerful heat flow in Asia. The monthly-averaged air temperature in the Northern Hemisphere was the same (to an accuracy of 0.1°) as the maximum value previously recorded in 2016.
April was cold In Moscow. Its average temperature was +4.8°, and the anomaly was  1.0°. In Moscow, a subnormal monthly-averaged air temperature was last observed in June of the previous year, and such cold April, just three years ago.

Ocean Surface Temperature

The ocean surface temperature in the Northern Hemisphere was still very high, especially in the Pacific Ocean. There, the SST anomalies were higher than +1° in a significant part of water area at middle latitudes and than +2° in individual regions. At the same time, the surface of the Ocean was abnormally cold along the eastern coast of Asia and the western coast of North America. The neutral phase of the Southern Oscillation was still active.
In the Atlantic Ocean, exceptionally warm water was observed in the Caribbean. This favoured the opening of the tropical hurricane development season. In certain regions, the anomalies were in excess of +2°. Cold water was still present at middle and northern latitudes from the coast of North America to the European coast, with the anomalies reaching -1° or more. However, the surface temperature of the marginal seas in Europe was above the normal value.


In the central and southern regions of the ETR, the precipitation was scarce in April: some half the normal monthly amount in the former ones, and even less in the latter. Yet, there were exceptions. For example, the monthly precipitation totals amounted to 1.5 times the normal value in the Ryazan and Tambov Regions, and to the normal value in the Kostroma, Ivanovo and Vladimir Regions. Occasionally, the precipitation intensity was so high that the normal monthly amount accumulated in just one day. The weather was arid in the Stavropol Territory where spring soil droughts replaced deadly winter frosts. Many crops died, and others stopped to grow. Snow returned to Central Russia from time to time and created a fresh snow cover up to half a meter high.
The picture was entirely different in the north and east of the ETR where the precipitation amounts were normal or higher than that. The most considerable amounts went to the Murmansk Region in the north and to the Republics of Mari El, Chuvashia, Mordovia and Tatarstan as well as the Penza Region in the east: twice the normal quantity or more. In these areas, snowfalls were still frequent and even resulted in blizzards sometimes.
In the Ural Region, the precipitation measured at one and a half to four times its normal amount. Winter returned there at the beginning of the month. Heavy snowfalls were reported in the Sverdlovsk, Kurgan and Chelyabinsk Regions. A similar situation occurred again at the end of the second decade, with wet snow and rain instead of snowfalls that time.
The abundant precipitation patterns in the Urals were reproduced in the neighbouring Omsk and Tomsk Regions an in the Taimyr Autonomous District. There, the monthly precipitation totals amounted to one and a half the normal value. The rest of Siberia received meagre precipitation this month – about half the normal value or less.
The conditions were similar in the Far East. Even though heavy rains with snow took place from time to time there (e.g., in the Amur Region and the Primorye Territory), the monthly precipitation totals reached the normal amount in Primorye, Sakhalin and Kamchatka only, while in the rest of the Far Eastern Federal District, only half of this amount was accumulated.
April in Mongolia was very dry, virtually with no precipitation. The same was true for the border regions of China. Yet in the most of China, the monthly precipitation amounts were just about half the normal value everywhere save for the western Yunnan and Sichuan provinces where they were normal or increased. The weather was dry on the Korean Peninsula. In Japan, the precipitation was about normal. Heavy showers took place in the middle of the month in this country; in Tokyo, more than 70% of the normal monthly amount fell for a single day only.
Heavy showers hit South-East Asia, causing floods and landslides in certain locations. The monthly precipitation totals were normal or above-normal in Vietnam, Thailand and Indonesia, up to two times the normal value in some places.
In the south and south-east of India and in the north of Pakistan, torrential rains resulted in floods. The monthly precipitation totals in individual regions of India were 2-3 or more times greater than the normal value. But the northern territories of India and the southern territories of Pakistan received almost no rains.
This month, the precipitation was abundant in the otherwise droughty Near and Middle East. The normal precipitation amounts were exceeded by 2-4 times in Iran and by 2 times in Yemen; this lead to floods in both these countries. Heavy rains fell on Lebanon: in Tripoli, they amounted to 98 mm of rainwater for one day, which is four times the normal monthly figure.
Rains fell in Algeria and in the countries adjacent to the Gulf of Guinea; the precipitation amounts in some places of these areas were 1.5-2.0 times greater then normal. Showers hit the east of Africa in the third decade of April. In Somali, Djibouti, Tanzania, Kenya, Chad and Ethiopia, they caused massive floods that injured hundreds of thousands of people, damaged tens of thousands of buildings and incurred huge economic losses.
Much precipitation was allotted to Central Asia where either normal or increased precipitation amounts were recorded almost everywhere. In the first decade of the month, Kazakhstan, Tajikistan and Kyrgyzstan were piled with snow reaching 20 cm in height. Such heavy snowfall has not been seen for a quarter of a century in Dushanbe. Southwards, snow turned into rain and caused flooding in Afghanistan.
In Spain and Portugal, abundant rains bringing 12-17 mm of rainwater per day took place in the first days of April. In the area of Valencia, they caused a flood that has not been seen there for more than thirty years. Rains in Spain poured in the following days as well to result in the monthly precipitation totals significantly exceeding the normal amount: e.g., by three times in some regions on the Mediterranean coast. Roughly at the same time, heavy rains came down on Greece and caused high floods. There, the normal precipitation amounts were also exceeded by 2-3 times. The precipitation was also above-normal in Norway where snowfalls still took place in the middle of the month and created a snow cover up to 50 cm high – which is quite rare for the middle of spring. The precipitation amounts were normal in the other Scandinavian countries as well as in the Baltic countries and in Belarus. The rest of Europe received small rainwater amounts, usually less than half their normal quantity. A catastrophic drought, worst for the last fifty years, took place in the Czech Republic. There, the soil moisture amounted to only 40% of the normal value. The restrictions on water consumptions were enforced in a number of cities.
Considering the precipitation, the territory of the USA can conveniently be divided into the East and West. The East, spreading from the Atlantic Coast roughly to Nebraska, Kansas and Oklahoma, received precipitation in either normal or increased amounts, two times the normal ones in some places. In the East and Middle West, snow was still falling to form a new snow cover several decimetres high. Further westward of this imaginary boundary, the precipitation amounts decreased to less than half the normal monthly totals as a rule. And only along the Pacific Coast, these normal totals were achieved or exceeded. The weather was dry in Mexico and in the other countries of Central America. In Canada, the precipitation was normal in the Labrador Peninsula, Quebec and the provinces of Saskatchewan and Manitoba, but scarce in the rest of the country.
In Moscow, 28 mm of precipitation was recorded. This is 64% of the normal value.