nomadseason

Monthly climate in Rumoi, Japan

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Rumoi features a humid continental climate (Dfb). Temperatures typically range between -5 °C (22 °F) and 21 °C (70 °F) through the year, but rarely can drop to -20 °C (-3 °F) or can rise to as high as 31 °C (89 °F). The average annual precipitation amounts to about 1283 mm (50.5 inches) and receives 189 rainy days on the 1 mm (0.04 inches) threshold annually. Rumoi enjoys an average of 2864 hours of sunshine throughout the year, and daylight varies from 8 hours 56 minutes to 15 hours 24 minutes per day.

Monthly average temperatures in Rumoi, Japan

The warmest months in Rumoi are July, August and September, with daily mean temperatures ranging from 18 to 21 °C (64 - 70 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from -5 to -2 °C (22 - 28 °F) throughout the day. On average each year, Rumoi experiences 14 days above 25 °C (77.0 °F) and 118 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Rumoi. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum6°C
(42°F)		7°C
(46°F)		14°C
(58°F)		19°C
(67°F)		27°C
(80°F)		24°C
(76°F)		31°C
(89°F)		31°C
(88°F)		28°C
(82°F)		21°C
(71°F)		15°C
(60°F)		12°C
(54°F)
Mean maximum3°C
(37°F)		5°C
(41°F)		10°C
(51°F)		16°C
(61°F)		21°C
(71°F)		21°C
(70°F)		28°C
(82°F)		29°C
(84°F)		26°C
(78°F)		20°C
(69°F)		15°C
(59°F)		8°C
(47°F)
Average high-3°C
(27°F)		-2°C
(29°F)		4°C
(39°F)		9°C
(48°F)		14°C
(58°F)		18°C
(64°F)		23°C
(74°F)		24°C
(75°F)		21°C
(70°F)		15°C
(59°F)		7°C
(45°F)		-0°C
(32°F)
Daily mean-5°C
(22°F)		-4°C
(24°F)		0°C
(33°F)		6°C
(42°F)		11°C
(52°F)		15°C
(59°F)		21°C
(69°F)		21°C
(70°F)		18°C
(64°F)		12°C
(53°F)		5°C
(41°F)		-2°C
(28°F)
Average low-9°C
(17°F)		-8°C
(19°F)		-3°C
(27°F)		2°C
(36°F)		8°C
(47°F)		12°C
(55°F)		18°C
(65°F)		19°C
(66°F)		15°C
(58°F)		8°C
(48°F)		2°C
(37°F)		-4°C
(24°F)
Mean minimum-15°C
(5°F)		-15°C
(5°F)		-9°C
(15°F)		-3°C
(26°F)		4°C
(39°F)		8°C
(46°F)		14°C
(58°F)		13°C
(56°F)		10°C
(50°F)		4°C
(39°F)		-3°C
(26°F)		-12°C
(11°F)
Minimum-20°C
(-3°F)		-18°C
(-1°F)		-12°C
(11°F)		-8°C
(19°F)		3°C
(38°F)		4°C
(39°F)		10°C
(50°F)		12°C
(54°F)		7°C
(45°F)		1°C
(34°F)		-5°C
(22°F)		-16°C
(4°F)

Compare climate in Rumoi with other places

Compare temperature, precipitation, sunshine, UV index in Rumoi, Japan with other places around the world.

Monthly average precipitation in Rumoi, Japan

Rumoi usually has the most precipitation in August, October and November, with an average of 18 rainy days and 157 mm (6.2 inches) of precipitation per month. The driest months in Rumoi are January, March and April. On average, 74 mm (2.9 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Rumoi. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)70 (2.8)84 (3.3)84 (3.3)67 (2.6)89 (3.5)94 (3.7)103 (4.0)171 (6.7)90 (3.6)147 (5.8)152 (6.0)132 (5.2)
Average precipitation days (≥ 1 mm)181915111112101512162327

Monthly sunshine hours in Rumoi, Japan

The sunniest months in Rumoi are May, June and July, when the sun shines an average of 9 hours 52 minutes a day. Least sunny months in Rumoi: January, November and December receive an average of 4 hours 57 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Rumoi. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours125182238285301288319287272232171160
Mean daily daylight hours9h 17m10h 27m11h 55m13h 26m14h 44m15h 24m15h 4m13h 56m12h 28m10h 58m9h 38m8h 56m

Solar UV radiation in Rumoi, Japan

Rumoi experiences the highest level of ultraviolet (UV) radiation in June, July and August, when the maximum UV index can reach values of 9 - 9, which corresponds to the Very High category of sun exposure. January, February and December are in the Low / Moderate exposure category. In these months, the maximum values of the UV index do not exceed 3. For more detailed information, check out our hourly Rumoi UV Index data.

Average daily maximum UV levels by month for Rumoi. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)235789998532