Climate - Lahti (Finland)

The climate of Lahti is cold continental, with freezing winters and mild summers.
The city is located in southern Finland, about 90 km (55 mi) north of Helsinki.
The white nights, when it doesn't get completely dark even at midnight, occur from May 9th to August 5th.
In winter, there can be cold spells of arctic origin. The coldest record is -35.6 °C (-32.1 °F) and was set in February 1967.
In summer, there can be short hot periods. The highest record is 35 °C (95 °F) and was set in July 2010.

Best Time

The best time to visit Lahti 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.

Lahti - Climate data

In Lahti, the average temperature of the coldest month (February) is of -6.4 °C (20.6 °F), that of the warmest month (July) is of 17.4 °C (63.3 °F). Here are the average temperatures.
In Lahti, precipitation amounts to 615 millimeters (24.2 inches) per year: so, it is at an intermediate level. It ranges from 30 mm (1.2 in) in the driest months (March, April) to 70 mm (2.8 in) in the wettest ones (July, August) Here is the average precipitation.

Lahti - Weather by month

Based on the period 1991-2020

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In January, the weather in Lahti is usually freezing cold. The average temperature is of -6.1 °C (21 °F), with a minimum of -9.1 °C (15.6 °F) and a maximum of -3 °C (26.6 °F).
On the coldest nights of the month, the temperature usually drops to around -23.5 °C (-10.5 °F). However, it dropped to -33 °C (-27.4 °F) in January 2003.
On the warmest days of the month, the temperature usually reaches around 4 °C (39 °F). However, it reached 9.5 °C (49.1 °F) in January 2019.
Precipitation amounts to 45 mm (1.8 in), distributed over 12 days.
The day lasts on average 6 hours and 35 minutes. So the days are short.
The average humidity is 87%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).

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In February, the coldest month of the year, the weather in Lahti is usually freezing cold. The average temperature is of -6.4 °C (21 °F), with a minimum of -9.8 °C (14.3 °F) and a maximum of -2.9 °C (26.8 °F).
On the coldest nights of the month, the temperature usually drops to around -24 °C (-11 °F). However, it dropped to -32.4 °C (-26.3 °F) in February 1996.
On the warmest days of the month, the temperature usually reaches around 4 °C (39 °F). However, it reached 7.8 °C (46 °F) in February 2015.
Precipitation amounts to 35 mm (1.4 in), distributed over 9 days.
The day lasts on average 9 hours and 5 minutes.
The average humidity is 85%. Hence, the air is normally humid.
The average wind speed is 10 kph (6 mph).

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In March, the weather in Lahti is usually very cold. The average temperature is of -2.3 °C (28 °F), with a minimum of -6.8 °C (19.8 °F) and a maximum of 2.1 °C (35.7 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -18.5 °C (-1 °F). However, it dropped to -26.9 °C (-16.4 °F) in March 2013.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 9.5 °C (49 °F). However, it reached 16.6 °C (61.9 °F) in March 2007.
Precipitation amounts to 30 mm (1.2 in), distributed over 8 days.
The day lasts on average 11 hours and 55 minutes.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).

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In April, the weather in Lahti is usually cold. The average temperature is of 3.9 °C (39 °F), with a minimum of -1.4 °C (29.6 °F) and a maximum of 9.1 °C (48.4 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -9 °C (15.5 °F). However, it dropped to -16.5 °C (2.3 °F) in April 1998.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 18.5 °C (65 °F). However, it reached 24.2 °C (75.6 °F) in April 1998.
Precipitation amounts to 30 mm (1.2 in), distributed over 7 days.
The day lasts on average 14 hours and 50 minutes.
The average humidity is 75%. Hence, the air is normally humid.
The average wind speed is 12 kph (7 mph).

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In May, the weather in Lahti is usually mild. The average temperature is of 10.0 °C (50 °F), with a minimum of 3.7 °C (38.7 °F) and a maximum of 16.3 °C (61.4 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -3.5 °C (25.5 °F). However, it dropped to -7 °C (19.4 °F) in May 1995.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 25 °C (77 °F). However, it reached 30.1 °C (86.2 °F) in May 1995.
Precipitation amounts to 40 mm (1.6 in), distributed over 8 days.
The day lasts on average 17 hours and 30 minutes. So the days are very long.
The average humidity is 67%.
The average wind speed is 12 kph (7 mph).

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In June, the weather in Lahti is usually mild. The average temperature is of 14.3 °C (58 °F), with a minimum of 8.5 °C (47.2 °F) and a maximum of 20.1 °C (68.2 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 1.5 °C (34.5 °F). However, it dropped to -1.8 °C (28.8 °F) in June 2017.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 27 °C (81 °F). However, it reached 32.1 °C (89.8 °F) in June 1999.
Precipitation amounts to 65 mm (2.6 in), distributed over 9 days.
The day lasts on average 19 hours and 5 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 67%.
The average wind speed is 12 kph (7 mph).

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In July, the warmest month of the year, the weather in Lahti is usually very mild. The average temperature is of 17.4 °C (63 °F), with a minimum of 11.6 °C (53 °F) and a maximum of 23.1 °C (73.6 °F).
On the coldest nights of the month, the temperature usually drops to around 5.5 °C (42.5 °F). However, it dropped to 1.8 °C (35.2 °F) in July 2009.
On the warmest days of the month, the temperature usually reaches around 28.5 °C (83.5 °F). However, it reached 35 °C (95 °F) in July 2010.
Precipitation amounts to 70 mm (2.8 in), distributed over 10 days.
The day lasts on average 18 hours and 10 minutes. So the days are very long.
The average humidity is 73%. Hence, the air is normally humid.
The average wind speed is 10 kph (6 mph).

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In August, the weather in Lahti is usually very mild. The average temperature is of 15.6 °C (60 °F), with a minimum of 10.1 °C (50.1 °F) and a maximum of 21.1 °C (70 °F).
On the coldest nights of the month, the temperature usually drops to around 3.5 °C (38 °F). However, it dropped to 0.6 °C (33.1 °F) in August 1994.
On the warmest days of the month, the temperature usually reaches around 27.5 °C (81 °F). However, it reached 33.8 °C (92.8 °F) in August 2010.
Precipitation amounts to 70 mm (2.8 in), distributed over 10 days.
The day lasts on average 15 hours and 35 minutes. So the days are long.
The average humidity is 80%. Hence, the air is normally humid.
The average wind speed is 10 kph (6 mph).

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In September, the weather in Lahti is usually mild. The average temperature is of 10.5 °C (51 °F), with a minimum of 5.8 °C (42.4 °F) and a maximum of 15.2 °C (59.4 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -2 °C (28.5 °F). However, it dropped to -8.4 °C (16.9 °F) in September 1993.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 21.5 °C (71 °F). However, it reached 25.2 °C (77.4 °F) in September 1991.
Precipitation amounts to 55 mm (2.2 in), distributed over 9 days.
The day lasts on average 12 hours and 50 minutes.
The average humidity is 86%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).

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In October, the weather in Lahti is usually quite cold. The average temperature is of 4.5 °C (40 °F), with a minimum of 1.1 °C (34 °F) and a maximum of 7.8 °C (46.1 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -8 °C (17.5 °F). However, it dropped to -16.5 °C (2.3 °F) in October 2002.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 14.5 °C (58 °F). However, it reached 18.8 °C (65.8 °F) in October 2018.
Precipitation amounts to 65 mm (2.6 in), distributed over 11 days.
The day lasts on average 10 hours and 0 minutes.
The average humidity is 87%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).

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In November, the weather in Lahti is usually very cold. The average temperature is of 0.0 °C (32 °F), with a minimum of -2.3 °C (27.8 °F) and a maximum of 2.4 °C (36.2 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -12.5 °C (9.5 °F). However, it dropped to -23.8 °C (-10.8 °F) in November 1995.
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 13.2 °C (55.8 °F) in November 2015.
Precipitation amounts to 60 mm (2.4 in), distributed over 11 days.
The day lasts on average 7 hours and 20 minutes. So the days are short.
The average humidity is 90%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).

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In December, the weather in Lahti is usually very cold. The average temperature is of -3.6 °C (26 °F), with a minimum of -6.2 °C (20.9 °F) and a maximum of -1 °C (30.3 °F).
On the coldest nights of the month, the temperature usually drops to around -19 °C (-2 °F). However, it dropped to -31.2 °C (-24.2 °F) in December 1995.
On the warmest days of the month, the temperature usually reaches around 4.5 °C (40.5 °F). However, it reached 10.4 °C (50.7 °F) in December 2015.
Precipitation amounts to 50 mm (2 in), distributed over 12 days.
The day lasts on average 5 hours and 40 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 89%. Hence, the air is normally humid.
The average wind speed is 12 kph (7 mph).