N. Europe: how’s the winter been so far?

This week, the lowest temperatures in Europe have been observed between Russia and the Balkans, with minimum temperatures close to -20 °C in some areas. Instead, in N. Europe, temperatures are not too low for being January, with maximum values above 0°C along the Atlantic coast of Norway up to the Arctic Circle (today maximum values between + 5-7 °C in the Lofoten Islands).

I have analysed and plotted the temperatures osberved in some cities in both Denmark, Sweden, Norway and Finland, to see if December and the first week of January have been colder compared to the climatological (long-term) average 1981-2010.

In Figure1 the main cities are shown. They are both in the mainland and along the coast.

Figure1. Cities chosen in the analysis

We can see how the lowest average temperatures (as also according to the climatological average) are observed in the mainland and far from the Atlantic Ocean, between N. Norway and Finland, where the warming effect of the Gulf stream is weaker.

The coldest city is Rovaniemi, with almost -20 °C observed in the minimum average values during the last week. The warmest, instead, is Copenhagen, with both minimum and maximum average temperatures observed during the last December above 0 °C. Also Trondheim (along the coast of Norway) is observing temperatures above 0 °C, especially during the last week.

Figure2. Maximum and minimum average temperatures observed in December 2018 (left) and first week of January 2019 (right).

The comparison with the climatological average (Figure3) shows a very clear result. Positive anomalies are osberved mostly everywhere, especially in the minimum average temperatures (both in December and January), with values up to 7 °C (e.g. Trondheim) above the long-term average.

Figure3. Maximum and minimum temperature anomaly calculated with respect to the climatological average 1981-2010. December (left), January (right).

It seems that the most significant anomalies occurr along the atlantic coast of Norway (Oslo, Trondheim, Tromso), instead moving eastward the anomalies are little (1 °C: Helsinki) or negative (Rovaniemi), though Oulu (Finland) observes significant positive anomalies (+3/+5 °C).

These ‘warm’ conditions are due to the very warm air moved northward during the past few weeks (from mid-Atlantic towards the UK and N. Atlantic); however, the areas close to Russia have been more influenced by the polar air moved towards Eastern-Central Europe, observing values closer or below the average.

The weather should be colder the next few days, especially along the Atlantic coast, due to an Arctic maritime air mass moving towards the N. Sea.

Now we need only to wait and see if the second part of January will show colder conditions (for these areas).


I have collect data from: https://www.meteociel.fr/observations-meteo/temperatures.php?region=nor