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Monthly climate in Siuntio, Finland

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Siuntio features a humid continental climate (Dfb). Temperatures typically range between -3 °C (26 °F) and 18 °C (64 °F) through the year, but rarely can drop to -22 °C (-8 °F) or can rise to as high as 32 °C (89 °F). The average annual precipitation amounts to about 757 mm (29.8 inches) and receives 139 rainy days on the 1 mm (0.04 inches) threshold annually. Siuntio enjoys an average of 3313 hours of sunshine throughout the year, and daylight varies from 5 hours 57 minutes to 18 hours 44 minutes per day.

Monthly average temperatures in Siuntio, Finland

The warmest months in Siuntio 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 March, when daily mean temperatures range from -3 to -1 °C (26 - 31 °F) throughout the day. On average each year, Siuntio experiences 10 days above 25 °C (77.0 °F) and 116 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Siuntio. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum8°C
(46°F)		6°C
(43°F)		10°C
(50°F)		19°C
(66°F)		26°C
(79°F)		29°C
(84°F)		32°C
(89°F)		28°C
(83°F)		22°C
(73°F)		16°C
(62°F)		12°C
(54°F)		7°C
(44°F)
Mean maximum4°C
(40°F)		4°C
(40°F)		8°C
(47°F)		14°C
(58°F)		22°C
(72°F)		24°C
(75°F)		28°C
(82°F)		25°C
(77°F)		20°C
(69°F)		15°C
(58°F)		10°C
(51°F)		6°C
(42°F)
Average high-0°C
(31°F)		-1°C
(30°F)		2°C
(36°F)		7°C
(45°F)		14°C
(57°F)		20°C
(68°F)		21°C
(71°F)		20°C
(68°F)		15°C
(59°F)		9°C
(49°F)		5°C
(41°F)		1°C
(34°F)
Daily mean-2°C
(28°F)		-3°C
(26°F)		-1°C
(31°F)		3°C
(39°F)		10°C
(50°F)		16°C
(61°F)		18°C
(64°F)		16°C
(62°F)		12°C
(54°F)		7°C
(45°F)		3°C
(38°F)		-1°C
(31°F)
Average low-5°C
(24°F)		-6°C
(22°F)		-4°C
(25°F)		-0°C
(32°F)		5°C
(41°F)		11°C
(53°F)		14°C
(57°F)		13°C
(55°F)		9°C
(49°F)		5°C
(41°F)		2°C
(35°F)		-2°C
(28°F)
Mean minimum-16°C
(3°F)		-15°C
(5°F)		-14°C
(6°F)		-7°C
(19°F)		-2°C
(29°F)		6°C
(42°F)		9°C
(48°F)		8°C
(46°F)		2°C
(36°F)		-3°C
(28°F)		-5°C
(24°F)		-9°C
(16°F)
Minimum-22°C
(-8°F)		-21°C
(-6°F)		-22°C
(-7°F)		-10°C
(14°F)		-3°C
(27°F)		3°C
(38°F)		7°C
(45°F)		7°C
(45°F)		-1°C
(31°F)		-4°C
(25°F)		-7°C
(19°F)		-18°C
(0°F)

Compare climate in Siuntio with other places

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

Monthly average precipitation in Siuntio, Finland

Siuntio usually has the most precipitation in July, August and October, with an average of 13 rainy days and 83 mm (3.3 inches) of precipitation per month. The driest months in Siuntio are February, April and June. On average, 47 mm (1.8 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Siuntio. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)58 (2.3)49 (1.9)54 (2.1)40 (1.6)53 (2.1)51 (2.0)83 (3.3)78 (3.1)65 (2.6)88 (3.5)63 (2.5)75 (2.9)
Average precipitation days (≥ 1 mm)1110119118111213161215

Monthly sunshine hours in Siuntio, Finland

The sunniest months in Siuntio are May, June and July, when the sun shines an average of 15 hours 28 minutes a day. Least sunny months in Siuntio: January, November and December receive an average of 2 hours 31 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Siuntio. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours5615426036044949148140329018911460
Mean daily daylight hours6h 46m9h 7m11h 51m14h 38m17h 14m18h 44m17h 55m15h 31m12h 47m10h 2m7h 27m5h 57m

Solar UV radiation in Siuntio, Finland

Siuntio 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 Siuntio UV Index data.

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