hav.fo/Karin M. H. Larsen Environment Head of Department, Ph.D, Oceanographer
Hot spring on the Continental Shelf
Sea temperatures were record highs in March, April and May. This is shown by temperature measurements from Oyrargjógv and Skopun.
The year started with low values in the first half of January, and the average temperature for January was therefore one winter below average.
In late January, the temperature rose and remained stable for most of February, until it rose sharply in the last days of the month, so that the average temperature for February was higher than for January. Both February and March are usually colder than January.
In March, temperatures rose even further, with the average temperature for March exceeding the record from March 2003.
In April and May, temperatures rose sharply, with these two months also exceeding the records from 2003 and 2011 respectively (Table 1).
Table 1. Warmest months on the continental shelf, measured at Mykines (1914-1969) and Oyrargjógv (1991-2024) (first column). The monthly average temperature so far in 2025 is in the next column, where the new records are in red.
Maybe 1. Warmest months on the continental shelf, measured at Mykines (1914-1969) and Oyrargjógv (1991-2024) (first column). The monthly average temperature so far in 2025 is in the next column, where the new records are in red.
Heitasti Manaði and Year (1914-2024)
Month Average (2025)
Jan
7.40 (2003)
6.85
Feb
7.14 (2006)
6.94
Mar
7.15 (2003)
7.25
Apr
7.61 (2003)
7.7
May
8.41 (2011)
8.54
Jun
9.24 (1960)
Jul
10.29 (2009)
Aug
10.99 (2009)
Sep
11.11 (2003)
Oct
10.42 (1959)
Nov
9.60 (2009)
Dec
8.40 (2009)
Hottest month and year (1914-2024)
Monthly average (2025)
Jan
7.40 (2003)
6.85
Feb
7.14 (2006)
6.94
Sea
7.15 (2003)
7.25
April
7.61 (2003)
7.7
Don’t
8.41 (2011)
8.54
Jun
9.24 (1960)
Christmas
10.29 (2009)
Aug
10.99 (2009)
Sep
11.11 (2003)
Oct
10.42 (1959)
November
9.60 (2009)
Some
8.40 (2009)
How is the sea warming?
The temperature of the continental shelf changes in two main ways: through the aquatic crust or by infiltration of the sea from outside.
Through the aquatic crust there is an exchange of heat between air and sea. In addition, the sea is heated by the sunlight that is absorbed in the crust or the upper layers of the sea.
Outside the continental shelf, the warm Atlantic Ocean flows on its way towards the Arctic. Some of this sea flows into the continental shelf and mixes with the continental shelf. This happens all the time; but the temperature of the Atlantic Ocean varies between years depending on the strength of the subpolar vortex.
Preliminary results from measurements in the Bank Stream indicate that the Atlantic Ocean is warmer than average this year.
Calculations also show that the subpolar melt was weak in 2024; this corresponds to the fact that the Atlantic Ocean has now become warmer.
This was also the result of Jákup Sverr’s survey trip in the second half of May, where the temperature in the crust in the research area was much higher than the last time these surveys were conducted in 2022 (see trip report here). And until recently, the air temperature in Torshavn was above average in March, April and May, according to the Meteorological Agency.
Thus, it seems that both the intrusion of warm seas from outside and the exchange of heat between air and sea played a role in the record hotness of these three months.
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