January 2021 was characterised by lower than normal mean sea surface pressure in the middle of the EFAS domain and higher than normal mean sea surface pressure towards the north. Monthly precipitation totals were above the long-term means especially at the Balkans and below normal around the Caspian Sea, Northern Africa, Iceland and Norway. Monthly mean air temperatures were below the long-term means in the west and the north of the EFAS domain and above in its easterly and southerly parts.

In the beginning of January 2021, the Azores High was slightly shifted northward, a low-pressure system was located around Jutland and another high-pressure system at the Ural Mountains. A secondary depression developed over the Ligurian Sea. This brought intense precipitation to Apennine Peninsula and the Balkans. The core of the high-pressure system moved towards Northern Scandinavia and later back to the northern Atlantic Ocean. A low-pressure system from the Atlantic Ocean moved along the southern edge of this high-pressure system towards the Strait of Gibraltar and later to the central Mediterranean Region. It caused strong precipitation in the Western Mediterranean Sea, e.g. also heavy snow at the Central Iberian Peninsula, and later at the Balkans. At the same time, a strong low-pressure system developed between Greenland and Iceland and moved with very strong winds to Southern Scandinavia. It weakened and moved further to Eastern Europe, where it intensified again and moved to the Artic Ocean. Next, a low-pressure system moved over the Atlantic Ocean to the Norwegian Sea and merged with another core at Great Britain and Ireland. Afterwards, it experienced a strong intensification while slightly moving northward and causing strong wind around the North Sea and the Norwegian Sea. This system split into several cores as it weakened. One of these resulting low-pressure systems moved southeastward towards the Aegean Sea and caused heavy precipitation there. Another core moved northeastward and intensified again.

In January 2021, the highest precipitation totals were observed in the northern Central and Eastern Mediterranean Region, Great Britain and Ireland and around the Alps, Bay of Biscay and Strait of Gibraltar (Figure 1). No or almost no precipitation fell in the south of the EFAS domain, eastward the Caspian Sea and in some parts of Norway. Monthly precipitation totals below the long-term means occurred in most of Norway, Iceland, around the Caspian Sea and in the majority of the African parts of the EFAS domain (Figure 2). Monthly totals above the long-term means were reported in large parts of the EFAS domain, especially at the Balkans, Apennines, around the Strait of Biscay and the Al Jabal Al Akhdar mountains in Libya.

The monthly mean air temperature ranged from -31.5°C to 20.2°C with the highest values in the southern parts of the EFAS domain. The lowest temperature values were reported in the northern, eastern and mountainous parts (Figure 3). Air temperature anomalies ranged from -13.5°C to 7.2°C (Figure 4). Monthly mean air temperatures below the long-term means occurred in the western and northern parts of the EFAS domain while positive temperature anomalies appeared in the east and south of the domain.