MAIN WEATHER AND CLIMATE TRAITS IN THE NORTHEN HEMISPHERE AS OF OCTOBER 2023
 
Air Temperature
 
Extreme warmth settled in the ETR at the end of September vanished at once in the first days of the next month and set either normal or subnormal air temperatures for almost all October, with the decade-averaged temperatures 2-3° less than normal in Central Russia and the frosts as cold as -3…-5° in the south (in the Krasnodar and Stavropol Territories, the Rostov Region and the republics of the North Caucasus). But at the end of the month, the summer weather returned to introduce many new air temperature maxima in the Smolensk and Bryansk Regions in the west, in the Lipetsk and Belgorod Regions in the centre, and in the Crimea, the Kherson and Zaporozhye Regions as well as the Krasnodar and Stavropol Territories in the south. In some locations, the thermometer readings would rise above 30°. In the Crimea, no such warmth at the end of October has been seen for more than fifty years.
A completely different picture was observed beyond the Urals. In Siberia and the Far East, almost the entire month was warmer than usual, and the decade-averaged temperature anomalies exceeded +4…7°. New daily temperature maxima, higher than +20° sometimes, were recorded in Siberia, Trans-Baikal and Kolyma, in the south of the Khabarovsk Territory, and on Sakhalin.

MAIN WEATHER AND CLIMATE TRAITS IN THE NORTHEN HEMISPHERE AS OF SEPTEMBER 2023
 Air temperature
 
At the beginning of the month, the weather in the ETR somewhat improved after the colds in the third decade of August: the temperatures approached the normal values or even noticeably exceeded them in the north where new daily maxima were set in the Murmansk and Arkhangelsk Regions, in the Nenets Autonomous District and Novaya Zemlya. The heat in the second decade spread further south and finally occupied the entire north-west of the country as well as Central Russia in part. The record-breaking maxima were now recorded in Karelia and in the Leningrad, Pskov, Kaliningrad, Moscow, Vladimir, Kostroma and some other Regions. But what happened in the third decade had never been observed this time of year before. The entire ETR and the Urals received much more heat than usual (with +2-6° anomalies), leading to record-breaking temperature maxima in many locations from the Baltic to the Urals, higher than +25° in places, and the air temperatures at the end of September matched those observed on a good summer day.
But beyond the Urals, cold days were more frequent. In Yakutia and in the north of the far East, negative anomalies of the decade-averaged temperatures reached -2…-3° and the thermometer readings could drop to -5…-10°, yet the abnormal heat would break through even there on occasional days: for example, the unprecedented temperature maxima were recorded at the beginning of the month in Trans-Baikal. At the end of September, heat came to Siberia, Yakutia and the south of the Far East, and new records of heat were established in Primorye, on Sakhalin and the Kuril Islands.