Weather and climate in Grimsey (Iceland)

The climate of Grimsey is subarctic, with cold winters and very cool summers, or even a little cold.
Grimsey is a small island located 40 km (25 mi) north of Iceland, and is the only point in the country to be crossed by the Arctic Circle (latitude 66°33'N).
However, thanks to the atmospheric refraction, the sun can be seen for a while even at the winter solstice, in fact, on December 21st, the sun rises at five minutes past noon and sets at 2:15 pm. Instead, on the longest days, the sun does not set (midnight sun) from June 7th to July 6th. Besides, the white nights, in which it is not completely dark even at midnight, occur before and after this period, from April 21st to August 23rd.
The average temperature of the coldest month (March) is of -0.3 °C (31.5 °F), that of the warmest month (August) is of 9 °C (48.2 °F). Here are the average temperatures.

Precipitation amounts to 325 millimeters (12.8 inches) per year: it is therefore scarce, at least in quantity, while it remains quite frequent all year round. Here is the average precipitation.

As is typical of Iceland, the weather is often unstable and windy.
In winter, there can be relatively mild periods, in which the temperature reaches 6/7 °C (43/45 °F). On the other hand, winds from the north pole or from Greenland can bring freezing periods of three or four days, in which the minimum temperature reaches -10 °C (14 °F) or below. The coldest record is -22.5 °C (-8.5 °F), recorded in March 1969, although the temperature has not dropped below -20 °C (-4 °F) since then. In the 1990s, it dropped to -16.5 °C (2.5 °F) in March 1992. In the 2010s, it only dropped to -11 °C (12 °F).
It usually snows from October to April or early May.
The summer is very cool, if not cold. The rains are quite frequent, although not abundant. However, there can be mild periods, usually of short duration, in which the temperature reaches or exceeds 15 °C (59 °F). The temperature almost never reaches 20 °C (68 °F), though the highest record is 22.2 °C (72 °F) and was set in July 1955.



The sea temperature ranges between 2 °C (36 °F) and 8 °C (46 °F). So, it is very cold all year round. Here are the average sea temperatures.

Best Time

The best time to visit Grimsey is the summer, from June to August, since it is the mildest season. However, there are often cloudy skies, rain and a bit of cold. Therefore, it is advisable to bring a jacket and a sweater even in the height of summer, and also hat, gloves and scarf for boat trips in search of whales.

Grimsey - Weather by month

Based on the period 1991-2020

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January is generally a cold month. The average temperature is of 0.4 °C (33 °F), with a minimum of -1.6 °C (29.1 °F) and a maximum of 2.3 °C (36.1 °F).
On the coldest nights of the month, the temperature usually drops to around -7.5 °C (18 °F). However, it dropped to -15.6 °C (3.9 °F) in January 1993.
On the warmest days of the month, the temperature usually reaches around 7.5 °C (45.5 °F). However, it reached 10.6 °C (51.1 °F) in January 1992.
Precipitation amounts to 25 mm (1 in), distributed over 18 days.
The day lasts on average 4 hours and 30 minutes. So the days are short.
The average humidity is 82%. Hence, the air is normally humid.
The average wind speed is 35 kph (22 mph).
The average sea temperature is of 3 °C (37 °F). Therefore, the sea is very cold for swimming.

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February is generally a very cold month. The average temperature is of -0.2 °C (32 °F), with a minimum of -2.2 °C (28 °F) and a maximum of 1.8 °C (35.2 °F).
On the coldest nights of the month, the temperature usually drops to around -8 °C (17 °F). However, it dropped to -14.6 °C (5.7 °F) in February 1998.
On the warmest days of the month, the temperature usually reaches around 7.5 °C (45.5 °F). However, it reached 11 °C (51.8 °F) in February 1997.
Precipitation amounts to 40 mm (1.6 in), distributed over 24 days.
The day lasts on average 8 hours and 10 minutes.
The average humidity is 82%. Hence, the air is normally humid.
The average wind speed is 34 kph (21 mph).
The average sea temperature is of 2.5 °C (36.5 °F). Therefore, the sea is very cold for swimming.

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March, the coldest month of the year, is generally a very cold month. The average temperature is of -0.2 °C (32 °F), with a minimum of -2.2 °C (28 °F) and a maximum of 1.7 °C (35.1 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -9.5 °C (15.5 °F). However, it dropped to -16.4 °C (2.5 °F) in March 1992.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 8 °C (46.5 °F). However, it reached 13 °C (55.4 °F) in March 1996.
Precipitation amounts to 30 mm (1.2 in), distributed over 17 days.
The day lasts on average 11 hours and 50 minutes.
The average humidity is 83%. Hence, the air is normally humid.
The average wind speed is 33 kph (20 mph).
The average sea temperature is of 2.5 °C (36.5 °F). Therefore, the sea is very cold for swimming.

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April is generally a cold month. The average temperature is of 1.0 °C (34 °F), with a minimum of -1 °C (30.2 °F) and a maximum of 2.9 °C (37.2 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -6 °C (21.5 °F). However, it dropped to -9.3 °C (15.3 °F) in April 2000.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 10 °C (50 °F). However, it reached 15.7 °C (60.3 °F) in April 2007.
Precipitation amounts to 25 mm (1 in), distributed over 21 days.
The day lasts on average 15 hours and 35 minutes.
The average humidity is 82%. Hence, the air is normally humid.
The average wind speed is 27 kph (17 mph).
The average sea temperature is of 2.5 °C (36.5 °F). Therefore, the sea is very cold for swimming.

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May is generally a quite cold month. The average temperature is of 4.0 °C (39 °F), with a minimum of 1.8 °C (35.2 °F) and a maximum of 6.1 °C (43 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -3 °C (26.5 °F). However, it dropped to -6.1 °C (21 °F) in May 1992.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 13 °C (55 °F). However, it reached 18.4 °C (65.1 °F) in May 1992.
Precipitation amounts to 10 mm (0.4 in), distributed over 12 days.
The day lasts on average 19 hours and 50 minutes. So the days are very long.
The average humidity is 83%. Hence, the air is normally humid.
The average wind speed is 23 kph (14 mph).
The average sea temperature is of 3.5 °C (38.5 °F). Therefore, the sea is very cold for swimming.

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June is generally a quite mild month. The average temperature is of 6.7 °C (44 °F), with a minimum of 4.5 °C (40.1 °F) and a maximum of 8.9 °C (48 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 1 °C (33.5 °F). However, it dropped to -2.4 °C (27.7 °F) in June 1997.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 15 °C (59 °F). However, it reached 18.1 °C (64.6 °F) in June 1999.
Precipitation amounts to 10 mm (0.4 in), distributed over 11 days.
The day lasts on average 23 hours and 50 minutes. So the days are very long. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
The average humidity is 85%. Hence, the air is normally humid.
The average wind speed is 22 kph (14 mph).
The average sea temperature is of 5.5 °C (42.5 °F). Therefore, the sea is very cold for swimming.

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July is generally a mild month. The average temperature is of 8.8 °C (48 °F), with a minimum of 6.7 °C (44.1 °F) and a maximum of 10.8 °C (51.4 °F).
On the coldest nights of the month, the temperature usually drops to around 4 °C (39 °F). However, it dropped to 0.7 °C (33.3 °F) in July 1995.
On the warmest days of the month, the temperature usually reaches around 16.5 °C (61.5 °F). However, it reached 21.7 °C (71.1 °F) in July 2011.
Precipitation amounts to 30 mm (1.2 in), distributed over 16 days.
The day lasts on average 21 hours and 25 minutes. So the days are very long.
The average humidity is 89%. Hence, the air is normally humid.
The average wind speed is 22 kph (14 mph).
The average sea temperature is of 7.5 °C (45 °F). Therefore, the sea is very cold for swimming.

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August, the least cold month of the year, is generally a mild month. The average temperature is of 9 °C (48 °F), with a minimum of 6.9 °C (44.4 °F) and a maximum of 11.1 °C (52 °F).
On the coldest nights of the month, the temperature usually drops to around 3.5 °C (38.5 °F). However, it dropped to 2 °C (35.6 °F) in August 1993.
On the warmest days of the month, the temperature usually reaches around 16 °C (60.5 °F). However, it reached 19.3 °C (66.7 °F) in August 2012.
Precipitation amounts to 30 mm (1.2 in), distributed over 15 days.
The day lasts on average 16 hours and 50 minutes. So the days are long.
The average humidity is 88%. Hence, the air is normally humid.
The average wind speed is 22 kph (14 mph).
The average sea temperature is of 8 °C (46.5 °F). Therefore, the sea is very cold for swimming.

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September is generally a quite mild month. The average temperature is of 7.0 °C (45 °F), with a minimum of 5.1 °C (41.2 °F) and a maximum of 9 °C (48.2 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 1 °C (33.5 °F). However, it dropped to -3.1 °C (26.4 °F) in September 1994.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 15 °C (58.5 °F). However, it reached 20.8 °C (69.4 °F) in September 2010.
Precipitation amounts to 35 mm (1.4 in), distributed over 20 days.
The day lasts on average 13 hours and 5 minutes.
The average humidity is 86%. Hence, the air is normally humid.
The average wind speed is 25 kph (16 mph).
The average sea temperature is of 6.5 °C (44 °F). Therefore, the sea is very cold for swimming.

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October is generally a cold month. The average temperature is of 3.8 °C (39 °F), with a minimum of 2 °C (35.6 °F) and a maximum of 5.5 °C (41.9 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -3 °C (27 °F). However, it dropped to -6.8 °C (19.8 °F) in October 1996.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 11 °C (52 °F). However, it reached 14.3 °C (57.7 °F) in October 2006.
Precipitation amounts to 30 mm (1.2 in), distributed over 22 days.
The day lasts on average 9 hours and 25 minutes.
The average humidity is 85%. Hence, the air is normally humid.
The average wind speed is 28 kph (17 mph).
The average sea temperature is of 5 °C (41 °F). Therefore, the sea is very cold for swimming.

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November is generally a cold month. The average temperature is of 1.8 °C (35 °F), with a minimum of 0 °C (32 °F) and a maximum of 3.6 °C (38.5 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -5 °C (23 °F). However, it dropped to -8.7 °C (16.3 °F) in November 2006.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 8.5 °C (47.5 °F). However, it reached 12.8 °C (55 °F) in November 1999.
Precipitation amounts to 30 mm (1.2 in), distributed over 21 days.
The day lasts on average 5 hours and 35 minutes. So the days are short.
The average humidity is 82%. Hence, the air is normally humid.
The average wind speed is 32 kph (20 mph).
The average sea temperature is of 4 °C (39 °F). Therefore, the sea is very cold for swimming.

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December is generally a cold month. The average temperature is of 0.5 °C (33 °F), with a minimum of -1.5 °C (29.3 °F) and a maximum of 2.5 °C (36.5 °F).
On the coldest nights of the month, the temperature usually drops to around -8 °C (17.5 °F). However, it dropped to -12.3 °C (9.9 °F) in December 1995.
On the warmest days of the month, the temperature usually reaches around 8 °C (46.5 °F). However, it reached 15 °C (59 °F) in December 1997.
Precipitation amounts to 25 mm (1 in), distributed over 20 days.
The day lasts on average 2 hours and 35 minutes. So the days are very short. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
The average humidity is 82%. Hence, the air is normally humid.
The average wind speed is 33 kph (20 mph).
The average sea temperature is of 3.5 °C (38 °F). Therefore, the sea is very cold for swimming.