Climate - Hanko (Finland)

The climate of Hanko is Baltic, that is, moderately continental, with cold winters, during which the average temperature is a few degrees below freezing, and mild to pleasantly warm summers.
Hanko (Hangö in Swedish) is located in the south-western tip of Finland, in the area where the climate is (relatively) milder.
The white nights, when it doesn't get completely dark even at midnight, occur from May 13th to July 31st.
In winter, there can be cold spells of arctic origin. The coldest record is -35.2 °C (-31.4 °F) and was set in February 1966.
In summer, there can be short hot periods. The highest record is 31.1 °C (88 °F) and was set in July 1983.

Best Time

The best time to visit Hanko is the summer, from June to August, since it is the mildest season. However, you must take into account some rainy days and a bit of cold at night.

Hanko - Climate data

In Hanko, the average temperature of the coldest month (February) is of -3.2 °C (26.2 °F), that of the warmest month (July) is of 17.7 °C (63.9 °F). Here are the average temperatures.
In Hanko, precipitation amounts to 630 millimeters (24.8 inches) per year: so, it is at an intermediate level. It ranges from 30 mm (1.2 in) in the driest month (April) to 80 mm (3.1 in) in the wettest one (August). Here is the average precipitation.
At Hanko, the sea temperature ranges from 1.5 °C (35 °F) in February, March to 17.5 °C (64 °F) in August. Here are the average sea temperatures.

Hanko - Weather by month

Based on the period 1991-2020

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In January, the weather in Hanko is usually very cold. The average temperature is of -2.2 °C (28 °F), with a minimum of -4.5 °C (23.9 °F) and a maximum of 0 °C (32.1 °F).
On the coldest nights of the month, the temperature usually drops to around -15.5 °C (4.5 °F). However, it dropped to -26.3 °C (-15.3 °F) in January 2003.
On the warmest days of the month, the temperature usually reaches around 4.5 °C (40.5 °F). However, it reached 7.7 °C (45.9 °F) in January 2020.
Precipitation amounts to 55 mm (2.2 in), distributed over 11 days.
The day lasts on average 6 hours and 55 minutes. So the days are short.
The average humidity is 87%. Hence, the air is normally humid.
The average wind speed is 20 kph (12 mph).
The average sea temperature is of 3 °C (37 °F). Therefore, the sea is very cold for swimming.

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In February, the coldest month of the year, the weather in Hanko is usually very cold. The average temperature is of -3.2 °C (26 °F), with a minimum of -5.6 °C (21.8 °F) and a maximum of -0.8 °C (30.5 °F).
On the coldest nights of the month, the temperature usually drops to around -15.5 °C (4.5 °F). However, it dropped to -24.5 °C (-12.1 °F) in February 2001.
On the warmest days of the month, the temperature usually reaches around 4.5 °C (39.5 °F). However, it reached 8.5 °C (47.3 °F) in February 2015.
Precipitation amounts to 40 mm (1.6 in), distributed over 9 days.
The day lasts on average 9 hours and 10 minutes.
The average humidity is 88%. Hence, the air is normally humid.
The average wind speed is 18 kph (11 mph).
The average sea temperature is of 1.5 °C (35 °F). Therefore, the sea is very cold for swimming.

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In March, the weather in Hanko is usually very cold. The average temperature is of -0.8 °C (31 °F), with a minimum of -3.5 °C (25.7 °F) and a maximum of 2 °C (35.5 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -12 °C (11 °F). However, it dropped to -22 °C (-7.6 °F) in March 2013.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 7.5 °C (45.5 °F). However, it reached 14.4 °C (57.9 °F) in March 2007.
Precipitation amounts to 35 mm (1.4 in), distributed over 8 days.
The day lasts on average 11 hours and 55 minutes.
The average humidity is 86%. Hence, the air is normally humid.
The average wind speed is 18 kph (11 mph).
The average sea temperature is of 1.5 °C (34.5 °F). Therefore, the sea is very cold for swimming.

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In April, the weather in Hanko is usually cold. The average temperature is of 3.8 °C (39 °F), with a minimum of 0.7 °C (33.3 °F) and a maximum of 6.8 °C (44.2 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -4 °C (24.5 °F). However, it dropped to -9.6 °C (14.7 °F) in April 2013.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 14 °C (57.5 °F). However, it reached 19.7 °C (67.5 °F) in April 2014.
Precipitation amounts to 30 mm (1.2 in), distributed over 7 days.
The day lasts on average 14 hours and 40 minutes.
The average humidity is 82%. Hence, the air is normally humid.
The average wind speed is 16 kph (10 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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In May, the weather in Hanko is usually mild. The average temperature is of 9.4 °C (49 °F), with a minimum of 5.8 °C (42.5 °F) and a maximum of 13.1 °C (55.5 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 0.5 °C (33 °F). However, it dropped to -1.9 °C (28.6 °F) in May 1999.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 21 °C (70 °F). However, it reached 25.5 °C (77.9 °F) in May 1992.
Precipitation amounts to 35 mm (1.4 in), distributed over 6 days.
The day lasts on average 17 hours and 10 minutes. So the days are very long.
The average humidity is 77%. Hence, the air is normally humid.
The average wind speed is 16 kph (10 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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In June, the weather in Hanko is usually mild. The average temperature is of 14.0 °C (57 °F), with a minimum of 10.5 °C (50.8 °F) and a maximum of 17.5 °C (63.5 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 6 °C (42.5 °F). However, it dropped to 3.3 °C (37.9 °F) in June 2009.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 23.5 °C (74.5 °F). However, it reached 27.6 °C (81.7 °F) in June 2009.
Precipitation amounts to 50 mm (2 in), distributed over 8 days.
The day lasts on average 18 hours and 40 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 76%. Hence, the air is normally humid.
The average wind speed is 16 kph (10 mph).
The average sea temperature is of 11 °C (52 °F). Therefore, the sea is very cold for swimming.

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In July, the warmest month of the year, the weather in Hanko is usually very mild. The average temperature is of 17.7 °C (64 °F), with a minimum of 14.3 °C (57.8 °F) and a maximum of 21.1 °C (70 °F).
On the coldest nights of the month, the temperature usually drops to around 10 °C (50 °F). However, it dropped to 7.9 °C (46.2 °F) in July 1992.
On the warmest days of the month, the temperature usually reaches around 26 °C (79 °F). However, it reached 30.9 °C (87.6 °F) in July 2019.
Precipitation amounts to 50 mm (2 in), distributed over 7 days.
The day lasts on average 17 hours and 50 minutes. So the days are very long.
The average humidity is 80%. Hence, the air is normally humid.
The average wind speed is 15 kph (9 mph).
The average sea temperature is of 16 °C (61 °F). Therefore, the sea is cold for swimming.

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In August, the weather in Hanko is usually very mild. The average temperature is of 16.9 °C (62 °F), with a minimum of 13.9 °C (57 °F) and a maximum of 20 °C (67.9 °F).
On the coldest nights of the month, the temperature usually drops to around 9 °C (48.5 °F). However, it dropped to 5.4 °C (41.7 °F) in August 2007.
On the warmest days of the month, the temperature usually reaches around 24.5 °C (76 °F). However, it reached 28 °C (82.4 °F) in August 2018.
Precipitation amounts to 80 mm (3.1 in), distributed over 9 days.
The day lasts on average 15 hours and 30 minutes. So the days are long.
The average humidity is 82%. Hence, the air is normally humid.
The average wind speed is 15 kph (9 mph).
The average sea temperature is of 17.5 °C (63.5 °F). Therefore, the sea is cold for swimming.

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In September, the weather in Hanko is usually mild. The average temperature is of 12.6 °C (55 °F), with a minimum of 10 °C (50 °F) and a maximum of 15.2 °C (59.3 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 4 °C (39 °F). However, it dropped to 0.8 °C (33.4 °F) in September 2013.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 19.5 °C (67.5 °F). However, it reached 23.2 °C (73.8 °F) in September 2002.
Precipitation amounts to 50 mm (2 in), distributed over 9 days.
The day lasts on average 12 hours and 50 minutes.
The average humidity is 83%. Hence, the air is normally humid.
The average wind speed is 18 kph (11 mph).
The average sea temperature is of 14.5 °C (58.5 °F). Therefore, the sea is very cold for swimming.

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In October, the weather in Hanko is usually quite mild. The average temperature is of 7.2 °C (45 °F), with a minimum of 5 °C (41 °F) and a maximum of 9.3 °C (48.8 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -2 °C (28 °F). However, it dropped to -9.2 °C (15.4 °F) in October 1992.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 14 °C (57 °F). However, it reached 16.1 °C (61 °F) in October 2011.
Precipitation amounts to 75 mm (3 in), distributed over 11 days.
The day lasts on average 10 hours and 0 minutes.
The average humidity is 85%. Hence, the air is normally humid.
The average wind speed is 19 kph (12 mph).
The average sea temperature is of 11 °C (51.5 °F). Therefore, the sea is very cold for swimming.

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In November, the weather in Hanko is usually cold. The average temperature is of 3.1 °C (37 °F), with a minimum of 1.2 °C (34.2 °F) and a maximum of 4.9 °C (40.8 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -6 °C (21.5 °F). However, it dropped to -13.7 °C (7.3 °F) in November 2010.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 9.5 °C (48.5 °F). However, it reached 12.2 °C (54 °F) in November 2015.
Precipitation amounts to 70 mm (2.8 in), distributed over 12 days.
The day lasts on average 7 hours and 30 minutes. So the days are short.
The average humidity is 86%. Hence, the air is normally humid.
The average wind speed is 21 kph (13 mph).
The average sea temperature is of 7.5 °C (45.5 °F). Therefore, the sea is very cold for swimming.

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In December, the weather in Hanko is usually cold. The average temperature is of 0.1 °C (32 °F), with a minimum of -2 °C (28.4 °F) and a maximum of 2.2 °C (35.9 °F).
On the coldest nights of the month, the temperature usually drops to around -10.5 °C (12.5 °F). However, it dropped to -22.4 °C (-8.3 °F) in December 2002.
On the warmest days of the month, the temperature usually reaches around 6 °C (43 °F). However, it reached 9.5 °C (49.1 °F) in December 2011.
Precipitation amounts to 60 mm (2.4 in), distributed over 13 days.
The day lasts on average 6 hours and 5 minutes. So the days are short. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
The average humidity is 88%. Hence, the air is normally humid.
The average wind speed is 21 kph (13 mph).
The average sea temperature is of 5 °C (41 °F). Therefore, the sea is very cold for swimming.