nomadseason

Monthly climate in Somero, Finland

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Somero features a humid continental climate (Dfb). Temperatures typically range between -4 °C (25 °F) and 18 °C (64 °F) through the year, but rarely can drop to -25 °C (-13 °F) or can rise to as high as 32 °C (90 °F). The average annual precipitation amounts to about 725 mm (28.5 inches) and receives 138 rainy days on the 1 mm (0.04 inches) threshold annually. Somero enjoys an average of 3353 hours of sunshine throughout the year, and daylight varies from 5 hours 48 minutes to 18 hours 55 minutes per day.

Monthly average temperatures in Somero, Finland

The warmest months in Somero are June, July and August, with daily mean temperatures ranging from 16 to 18 °C (61 - 64 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from -4 to -1 °C (25 - 30 °F) throughout the day. On average each year, Somero experiences 13 days above 25 °C (77.0 °F) and 135 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Somero. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum8°C
(47°F)		7°C
(44°F)		12°C
(54°F)		21°C
(69°F)		27°C
(82°F)		31°C
(88°F)		32°C
(90°F)		30°C
(86°F)		24°C
(75°F)		17°C
(63°F)		13°C
(55°F)		6°C
(43°F)
Mean maximum4°C
(40°F)		4°C
(40°F)		10°C
(50°F)		16°C
(61°F)		24°C
(75°F)		25°C
(78°F)		29°C
(84°F)		26°C
(79°F)		21°C
(70°F)		15°C
(59°F)		10°C
(51°F)		5°C
(42°F)
Average high-1°C
(31°F)		-1°C
(30°F)		2°C
(37°F)		8°C
(46°F)		14°C
(58°F)		21°C
(70°F)		22°C
(72°F)		20°C
(68°F)		15°C
(59°F)		9°C
(48°F)		4°C
(40°F)		0°C
(33°F)
Daily mean-3°C
(27°F)		-4°C
(25°F)		-1°C
(30°F)		4°C
(39°F)		10°C
(50°F)		16°C
(62°F)		18°C
(64°F)		16°C
(61°F)		11°C
(53°F)		6°C
(44°F)		3°C
(37°F)		-1°C
(30°F)
Average low-6°C
(22°F)		-7°C
(19°F)		-5°C
(24°F)		-1°C
(30°F)		4°C
(40°F)		11°C
(51°F)		13°C
(55°F)		12°C
(53°F)		8°C
(46°F)		4°C
(39°F)		1°C
(33°F)		-3°C
(26°F)
Mean minimum-18°C
(-1°F)		-18°C
(-0°F)		-16°C
(3°F)		-9°C
(17°F)		-3°C
(26°F)		5°C
(41°F)		7°C
(45°F)		6°C
(43°F)		0°C
(32°F)		-5°C
(24°F)		-7°C
(20°F)		-10°C
(14°F)
Minimum-25°C
(-13°F)		-24°C
(-12°F)		-25°C
(-12°F)		-13°C
(10°F)		-5°C
(22°F)		2°C
(35°F)		5°C
(41°F)		6°C
(43°F)		-4°C
(26°F)		-6°C
(21°F)		-10°C
(15°F)		-20°C
(-3°F)

Compare climate in Somero with other places

Compare temperature, precipitation, sunshine, UV index in Somero, Finland with other places around the world.

Monthly average precipitation in Somero, Finland

Somero usually has the most precipitation in July, August and October, with an average of 13 rainy days and 82 mm (3.2 inches) of precipitation per month. The driest months in Somero are February, March and April. On average, 44 mm (1.7 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Somero. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)51 (2.0)45 (1.8)49 (1.9)39 (1.5)59 (2.3)56 (2.2)81 (3.2)84 (3.3)59 (2.3)79 (3.1)54 (2.1)68 (2.7)
Average precipitation days (≥ 1 mm)11911111110111312151014

Monthly sunshine hours in Somero, Finland

The sunniest months in Somero are May, June and July, when the sun shines an average of 15 hours 30 minutes a day. Least sunny months in Somero: January, November and December receive an average of 2 hours 35 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Somero. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours5715626236445349048241029919411762
Mean daily daylight hours6h 38m9h 4m11h 51m14h 41m17h 21m18h 55m18h 4m15h 35m12h 48m10h 0m7h 21m5h 48m

Solar UV radiation in Somero, Finland

Somero experiences the highest level of ultraviolet (UV) radiation in June, July and August, when the maximum UV index can reach values of 5 - 7, which corresponds to the Moderate / High category of sun exposure. January, February and November are in the Low exposure category. In these months, the maximum values of the UV index do not exceed 1. For more detailed information, check out our hourly Somero UV Index data.

Average daily maximum UV levels by month for Somero. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)113457754211