MAIN WEATHER AND CLIMATE TRAITS IN THE NORTHEN HEMISPHERE AS OF DECEMBER 2023
 
Air Temperature
 
The abnormal colds which occupied the northern and central regions of the ETR in the last decade of November intensified even more at the beginning of December. In the first decade, the air temperature was short of 6-10° to reach its normal value. The thermometer readings dropped to -35° in Karelia and to -40° or below in Udmurtia, Bashkiria and the Perm Territory, with new daily minima of air temperatures recorded in the Volga region. A sharp break of temperature patterns occurred in the middle of the month and brought anomalous heat that prevailed across the whole ETR in the third decade. New daily temperature maxima were measured at times everywhere from the Volga to the Urals.
The reign of cold in the first and second decades extended beyond the Urals: the average temperatures were 6-12° below normal in the south of Siberia, and the recorded frosts were colder than -40° in Western Siberia, in the Irkutsk Region, in the Trans-Baikal and in the Primorye Territory, than -50° in Kolyma, and than -60° in Yakutia. New daily temperature minima were set in Buryatia, in the Trans-Baikal Territory, and on Sakhalin.
In the third decade, these anomalous colds survived in the Far East only where the temperature averages were 4-8° below normal in Yakutia, Kolyma and the Khabarovsk Territory, in contrast to Siberia where anomalous warmth came to set new daily temperature maxima in the south and in Yakutia. In the midst of winter, the thermometers in the Khabarovsk Territory showed above +5°.

MAIN WEATHER AND CLIMATE TRAITS IN THE NORTHEN HEMISPHERE AS OF NOVEMBER 2023
 
Air Temperature
 
Warm October handed the baton over November, the last autumn month. In the first decade, numerous unprecedented highs of warmth were recorded all over the ETR, and the decade-averaged temperature anomalies in Central Russia and in the south of the ETR reached +4…6° or more degrees. In the second decade, the Arctic colds permeated to the north of the ETR, and the decade-averaged temperature anomalies became negative in the Murmansk Region and in Karelia, while in Central Russia, the air temperatures were about normal. The abnormal warmth was still observed in the south only, even though the anomalies themselves were noticeably weaker now. The third decade was the point when an avalanche of colds triggered in the north and in the northern regions of Central Russia to produce new daily temperature minima in the Kaliningrad Region and to bring the frosts down to -27° in Karelia. The decade-averaged temperatures in the Murmansk and Arkhangelsk Regions and in Karelia were 2-6° less than normal. But in the south, the weather was untimely warm again, setting new daily maxima in the Lower Volga, the Luhansk and Rostov Regions and the Krasnodar Territory, and raising the thermometer readings above +20° to create new daily highs in some places.
Throughout the month, above-normal decade-averaged temperatures were observed along the Arctic coast from Yamal to Yakutia. In Siberia, the beginning and the end of November were cold. As early as in the first decade of the month, frosts reached -30…-40° in the Irkutsk Region, in Yakutia and in the north of the Khabarovsk Territory, and -22° in the Kemerovo Region in the south of Siberia. November ended with the record-breaking frosts in the Khabarovsk Territory, but the weather in the middle of the month was considerably warmer than usual in Siberia. The air temperature averages in the second decade were 6-13° higher than normal. The Irtysh River, with its average freezing date taken for November 17 in the Omsk region, was still rolling its water flows in the middle of the third decade.