An analysis of meteorological observations and the spectral analysis of the daily air temperature anomalies have
shown that the hot summers and the severe winters caused by the beats (slow periodic variations in the resulting
amplitude) of the interacting temperature oscillations with close frequencies. The 35-year basic period of beats in the
temperature and other hydrometeorological characteristics takes place due to the interference between their oscillations
with periods of solar (365 days) and lunar (355 days) years. In 2010 over European Russia, the phases of the "solar"
annual oscillations of hydrometeorological characteristics coincided with those of their basic "lunar" oscillations. As a
result, the amplitudes of these oscillations added up and reached extreme values.
Time series of the amount of sunshine are analyzed. It is shown that cycle with characteristic time about 35
years and quasi four-year fluctuations of the large amplitude manifest themselves in changes in cloud amount and the
amount of sunshine. The revealed cycles are generated by lunisolar tides.
The quasi 35-year changes of the cloud amount lead to fluctuations of the radiating balance. The amplitude of
these fluctuations increases with the growth of latitude and becomes especially high in polar areas where the day
(summer) and the night (winter) can last half a year. Big fluctuations of the thermal regime of polar areas generate
radical disturbances of the interhemisphere circulation that lead to greater anomalies of the exchange of the air masses,
heat, water vapour and pollution between the northern and southern hemispheres. These processes are responsible for
the epochs of the atmospheric circulation, the decade variations in the intensity of the Indian monsoon, changes of the
ice masses in Antarctica and Greenland that lead to the decade variations in the parameters of the Earth’s rotation.