MOSCOW, September 3. /TASS/. Russian weather watchers say the summer of 2015 was the warmest ever recorded in the Northern Hemisphere during the 125-year-long period of systematic weather observations on the globe.

"Over a very vast area of the hemisphere the average air temperatures were noticeably above normal. First and foremost this phenomenon was observed in Europe, the Middle East and South-West Asia, and also in Central Asia, Mexico, the western states of the US and in Alaska," the Russian weather watching centre said. On the average, summer temperatures were two to three degrees above normal. Air temperatures in the Western Atlantic over the warm current Gulf Stream and in the tropical latitudes of the Pacific Ocean, where the effects of the El Nino phenomenon are felt, were considerably higher than usual.

In Russia, last summer was in the top ten warmest ones in the whole history of weather watching. The role of the country’s Asian regions was the greatest. East of the Urals the average summer temperature was invariably above normal. In a greater part of Siberia it was two degrees Celsius higher than usual, in the Lake Baikal Area, three degrees and more. In the Chukchi Peninsula the summer was two degrees warmer than always. In the Siberian Federal District last summer was third hottest ever after those of 2001 and 2002.

At the same time in the northern European areas of Russia the summer was cold. Slight frosts were registered in July. Last time the summer months were as cold in 1996 - 20 years ago.

Unusually cold air masses prevailed last summer over the northern areas of the Atlantic and Pacific oceans. The Scandinavian countries and some areas of India and China felt their effects.

"The record-high air temperatures last winter, summer and spring, and the El Nino cycle of temperature oscillations, which may last till the end of the year, or possibly longer, indicate that 2015 will prove the warmest ever in the Northern Hemisphere," the weather watching centre said.