THE MAIN WEATHER AND CLIMATE FEATURES OF THE NORTHERN HEMISPHERE IN MAY 2018

Air Temperature.

During at least two last years (2016 and 2017) every month the average monthly air temperature in the Northern Hemisphere was in the first five highest values on the record, i.e. since 1891. However, the situation has been changed in the beginning of 2018. In January, the average monthly air temperature got 6th rank, and then it reached the end of the second five values, in February – 9th rank, in April – 8th one. May continued this tendency. Its average monthly air temperature holds 7-12 line among the highest ranged values.
Oceans are responsible substantially for the cold anomalies of the last May. In the north of Indian ocean, in the north and south of Atlantic and central part of Pacific oceans the average monthly air temperature became lower the norm, at some places by 2° and lower. In the continents, the cold dominated in a lot of Northern Hemisphere regions.
First of all, it is Canada, in the north-east of which the average monthly air temperature is above the norm by 2-4° and more. But in comparison with the south neighbour – USA- this warmth can be considered as not apparent, because in all US territory in May the warm, sometimes hot weather dominated. In all country territory, the average monthly air temperatures exceeded the norms by 2° and more, in the centre and Pacific coast – by 4-6° and more. In some places, the temperature was higher 35°. Warm air was transferred far to the east to the Atlantic ocean, in subtropical latitudes of it the May average air temperature exceeded the norm by 2-4°. In USA, the last May became the warmest one on the record in the country. The previous record achievement of the average monthly air temperature was exceeded by more than 0.5°. In Mexico, it was very warm, especially in the north of the country.

THE MAIN WEATHER AND CLIMATE FEATURES OF APRIL 2018 IN THE NORTHERN HEMISPHERE

Air Temperature.

April in the north-east of Russia commenced with the abnormally warm weather. In Chukotka and Yakutia in the first decade the new daily air temperature maximums were registered repeatedly. Decade norms were exceeded here by 4-10°. Then the warmth was spread in all east region of the country: from Urals to the Pacific ocean. In the second and third decades the air temperature noticeably exceeded the norms also in the south of Far East and in Siberia. As a result, the last April became here substantially warmer than usual – by 2-8°. In the north of Far East, it was the third warmest April on the record. Let us remind that April of the last year was recognized the warmest one in the region.
Quite another situation took place in the European territory of the country. Here the air temperature above the norm was kept all month only in the extreme west areas and in the north during the first decade. Other days of the month were fresh and sometimes – cold. In Central Russia and Chernozem area during the night the temperature dropped to -4°, in the south (Volgograd area and Krasnodar district) – the frosts were registered. As a result, in the most part of ETR and Urals the average monthly air temperatures became close to the norm. In Volga area and Urals, it was slightly colder than usual. The last April became warmer the norm in the west areas of Central and North-West Federal districts and in Crimea.