MAIN WEATHER AND CLIMATE TRAITS IN THE NORTHERN HEMISPHERE AS OF OCTOBER 2024

Air Temperature

In the first decade of October, the air temperature in most of the Russian Federation was approximately normal, with the exception of the central and southern regions of the ETR where the weather was warmer than usual by 2-4 or more degrees, and new daily temperature maxima were even recorded in some locations. But at the same time, new temperature minima were set in the south of Western Siberia and of the Krasnoyarsk Territory.

In the second decade, abnormal colds occupied almost the entire country, the weather in the south of Siberia became extremely cold, new temperature minima were recorded in the Novosibirsk Region and the Altai Territory, and the areas with the weather warmer than usual reduced to the Russian North and Kolyma where the decade-averaged temperatures were 2-3 or more degrees above normal. New temperature maxima were measured in the Arkhangelsk Region and the Republic of Karelia.

In the third decade, a significant part of Russia was invaded by the air which was abnormally warm that time, and the cold weather only prevailed in Taimyr and Evenkiya, in the central regions of the Khabarovsk Territory and partly in the North Caucasus. The northern and central regions of the ETR, the Urals, and the north and south of the Far East were now dominated by the warmth. The decade-averaged temperature anomalies reached 2-4 or more degrees, and new positive extremes of air temperature were repeatedly recorded in the Russian North, in central Russia, Western Siberia, Kamchatka and the Kuril Islands as well as on the Arctic Islands beyond the Arctic Circle.

As a result, the monthly-averaged air temperature in most of the country was above normal: by 1-2 or more degrees above in the ETR, by 1-3 or more degrees above in the north-east, and 3-6 or more degrees above on the Arctic Islands. The month was colder than usual in part of the Southern Urals, as well as in Yakutia and Evenkiya. The October temperature monthly-averaged over the entire Russia was among the second ten highest-ranked values recorded in 1891-2024.

In East Asia, warm weather prevailed. The normal monthly-averaged air temperatures in Japan and in some regions of China were exceeded by two or more degrees. In the latter country, this October was the third warmest in the history of observations.

The temperatures in South-East Asia were approximately normal.

The weather in India was very warm: the average October temperatures in the north of the country and in neighbouring Pakistan were two or more degrees higher than normal. This October in India was the warmest since 1891.

The monthly-averaged temperature in the Near East was close to normal. In Israel, this October can be considered cold: the lowest temperatures since 1991 were recorded in the coastal and low-lying areas of this country.

The air temperatures in Central Asia were close to normal as well. In northern Kazakhstan, cold weather which is rare for this time of year was observed in the middle of the month, the thermometer readings dropped to -10° and below, and new temperature minima were set in some places.

The monthly-averaged air temperatures in most of North Africa were about normal, but in some places (in Algeria, Niger and Chad) were noticeably higher than that.

The all-time warmest weather in October was observed in the Scandinavian countries where the air temperatures on some days exceeded +20° and new temperature maxima were set. The temperature patterns in the rest of the European continent roughly conformed to the normal ones.

This October in North America was very warm; it was the second warmest in the meteorological history of Canada and the United States. Moreover, Octobers in the last four years (2021-2024) were the warmest in the history of Canada. As for the US, October was the warmest in the history of the south-western states of Arizona, New Mexico, Utah and Colorado. Eventually, the average October temperature was two or more degrees higher than normal in most of North America, and 4-8 or more degrees higher in the north of Canada. The weather was slightly cooler than usual in Alaska and its neighbouring Canadian regions only.

This month in the Arctic was very warm: its average temperature occupied the second position in the ranking list due to very high temperatures all the way from Canada to Chukotka.

Regarding the entire Northern Hemisphere, October 2024 was the second warmest since 1891, October 2023 remaining the leader.

In Moscow, the average temperature in October was +7.7°, implying an anomaly of +1.9°, which is the tenth result in the meteorological chronicle of the capital. The average air temperature calculated for the ten past months of this year is the second highest in the history of meteorological observations.

Sea Surface Temperature

For the thirteenth month in a row since October 2023, the monthly-averaged SST of the Pacific Ocean in the Northern Hemisphere reached its absolute maximum again despite that El Niño has long ended, and a neutral phase of the Southern Oscillation with weak negative SST anomalies was active at equatorial latitudes. Similar anomalies took place in the north of the Ocean, but the rest of the water area was occupied by positive anomalies that exceeded +2…4° at subtropical and temperate latitudes.

The SST of the Atlantic Ocean in the Northern Hemisphere was ranked as the second maximum after the record-breaking value dated last year. The SST anomalies in the Ocean were positive almost everywhere in the Northern Hemisphere, and reached +2 or more degrees at tropical and temperate latitudes. Abnormally warm water was observed in the marginal seas of Europe, namely, in the Black, Mediterranean and Baltic seas. The SST in the Norwegian, Barents and Kara seas in the north was 1-3 or more degrees higher than normal.

Precipitation

The drought in the south of the central region of the ETR survived in October. In the Black Earth region, this drought lasted ever since summer. In certain regions, not a drop of rain has fallen for several months. The monthly precipitation totals in the rest of the Central Federal District were somewhat above normal, up to 1.5 or more times above in the western regions such as the Smolensk and Bryansk ones. In the north of the ETR as well as in the Upper and Middle Volga regions, precipitation was normal, while in the Cis-Urals, viz., in the Perm Territory, Bashkiria and Udmurtia, precipitation was scarce.

At the end of the second decade, unprecedented rains fell in the south of Russia, bringing more than 10-15 mm of daily rainwater to some places, and setting new daily maxima in a number of locations. The monthly precipitation totals in the Southern and North Caucasian federal districts were normal, or slightly higher than that in some places. The same was true for the Donetsk and Luhansk People's Republics.

The weather was dry in the Urals and approximately normal in Siberia. In the middle of the month, heavy snowfall hit the Altai Territory. Precipitation in the Far East was abundant: its monthly totals in the north-east were 1.5-2.0 or more times the normal amount in the Magadan Region, in the Chukotka Autonomous District and in the north of the Kamchatka Territory. Heavy downpours were observed in the south, namely, in the Primorye Territory as well as in the Amur and Sakhalin Regions; there, up to 30-50 mm of atmospheric moisture accumulated per day in places, and new daily maxima were set in some locations.

In China, the monthly precipitation totals were 2-3 or more times greater than normal in the north-eastern, eastern and central regions, whereas in the west and south of the country, rains were lacking. Precipitation in Japan and on the Korean Peninsula was close to normal.

The weather in India remained rainy, with the normal monthly precipitation amounts significantly exceeded in the south of the country. In mid-October, heavy rains hit Sri Lanka, causing floods and affecting more than seventy thousand people; the fatalities were reported.

In the Near and Middle East, heavy rains fell in the north of Iran and in Azerbaijan against the background of dry weather. There, the monthly precipitation totals were deemed exceptional, i.e., in excess of three normal monthly amounts. A lot of rain was also observed in the Central Asian republics where the monthly rainwater totals reached or exceeded the normal figure almost everywhere. The north of Kazakhstan was the only exception to fall short of rain.

A huge amount of atmospheric moisture was received by the western and central regions of North Africa where the normal figures were exceeded by 2-3 times. Heavy downpours led to catastrophic destruction in Liberia and caused floods in Mali that affected more than 250 thousand people. In the south-east of Morocco, the normal annual amount of precipitation fell in two days in the Sahara desert; as reported, the rains of such intensity have not been seen for more than thirty years in Morocco. In Chad, over two million people have suffered from rains as well as from the ensuing floods and landslides. Heavy showers and floods deluged a number of settlements in Senegal. No natural disaster of such scale has been observed in these countries for the last seventy years. In Nigeria, Chad, Mali, Guinea, Niger, Cameroon, Togo and Liberia, hundreds of deaths alongside vast destructed agricultural lands were reported in 2024 as a result of showers and their consequences such as floods and landslides.

In Europe, significant quantities of precipitation went to the western, central and northern territories of the continent; there, the normal monthly amounts were exceeded by two or more times. In contrast, rains in the east were rare: heavy rains were only observed at the beginning of the month in the Balkans where they caused numerous floods that have not been seen in the last ten years in Bosnia and Herzegovina. Showers were frequent in France, Germany, Denmark, Sweden, Norway and the north of Italy, bringing up to 30-70 mm of daily rainwater and setting new maximum levels of river rise in some regions. Floods in France and northern Italy were called the most severe in the last forty years. At the end of the month, heavy rains in the south and east of Spain caused floods in the provinces of Valencia and Andalusia, resulting in broken bridges, inundated city streets, and fatalities. The annual rainwater amount fell in several hours in some places. These floods were recognised as the most severe in the last half century in Spain.

The weather in North America was mostly dry. In the USA, this October was the driest in the history of regular meteorological observations. The normal precipitation amounts were reached in the coastal areas of Canada and on the eastern coast of Mexico only.

In Moscow, the monthly precipitation total amounted to 89 mm, which is 127% of the normal value.