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Monthly climate in Niimi, Japan

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Niimi features a humid subtropical climate (Cfa). Temperatures typically range between 2 °C (37 °F) and 26 °C (79 °F) through the year, but rarely can drop to -9 °C (15 °F) or can rise to as high as 35 °C (96 °F). The average annual precipitation amounts to about 1763 mm (69.4 inches) and receives 141 rainy days on the 1 mm (0.04 inches) threshold annually. Niimi enjoys an average of 2891 hours of sunshine throughout the year, and daylight varies from 9 hours 50 minutes to 14 hours 27 minutes per day.

Monthly average temperatures in Niimi, Japan

The warmest months in Niimi are July, August and September, with daily mean temperatures ranging from 22 to 26 °C (71 - 79 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from 2 to 4 °C (37 - 40 °F) throughout the day. On average each year, Niimi experiences 83 days above 25 °C (77.0 °F) and 58 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Niimi. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum12°C
(54°F)		20°C
(69°F)		23°C
(73°F)		26°C
(80°F)		31°C
(87°F)		31°C
(87°F)		35°C
(95°F)		35°C
(96°F)		32°C
(90°F)		29°C
(85°F)		22°C
(73°F)		18°C
(65°F)
Mean maximum11°C
(53°F)		15°C
(59°F)		20°C
(68°F)		25°C
(76°F)		29°C
(84°F)		29°C
(84°F)		33°C
(91°F)		34°C
(94°F)		31°C
(87°F)		28°C
(82°F)		21°C
(70°F)		15°C
(59°F)
Average high6°C
(44°F)		7°C
(46°F)		13°C
(55°F)		17°C
(64°F)		22°C
(72°F)		25°C
(77°F)		28°C
(83°F)		30°C
(87°F)		25°C
(78°F)		20°C
(69°F)		15°C
(59°F)		9°C
(48°F)
Daily mean2°C
(37°F)		3°C
(38°F)		8°C
(46°F)		12°C
(54°F)		17°C
(63°F)		21°C
(69°F)		25°C
(77°F)		26°C
(79°F)		22°C
(71°F)		16°C
(61°F)		10°C
(50°F)		4°C
(40°F)
Average low-1°C
(31°F)		-1°C
(31°F)		3°C
(37°F)		7°C
(44°F)		12°C
(54°F)		16°C
(62°F)		22°C
(71°F)		23°C
(73°F)		18°C
(65°F)		12°C
(54°F)		5°C
(42°F)		1°C
(34°F)
Mean minimum-5°C
(23°F)		-5°C
(23°F)		-2°C
(28°F)		-1°C
(31°F)		5°C
(41°F)		11°C
(53°F)		18°C
(65°F)		18°C
(65°F)		12°C
(54°F)		6°C
(42°F)		-1°C
(31°F)		-3°C
(28°F)
Minimum-8°C
(18°F)		-9°C
(15°F)		-2°C
(28°F)		-2°C
(28°F)		2°C
(36°F)		9°C
(49°F)		17°C
(62°F)		15°C
(59°F)		11°C
(52°F)		4°C
(40°F)		-2°C
(29°F)		-3°C
(27°F)

Compare climate in Niimi with other places

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

Monthly average precipitation in Niimi, Japan

Niimi usually has the most precipitation in July, August and September, with an average of 16 rainy days and 276 mm (10.8 inches) of precipitation per month. The driest months in Niimi are January, February and November. On average, 50 mm (2.0 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Niimi. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)52 (2.1)59 (2.3)116 (4.5)127 (5.0)115 (4.5)186 (7.3)356 (14.0)242 (9.5)229 (9.0)181 (7.1)37 (1.5)62 (2.4)
Average precipitation days (≥ 1 mm)10101210101420151410511

Monthly sunshine hours in Niimi, Japan

The sunniest months in Niimi are May, June and August, when the sun shines an average of 9 hours 15 minutes a day. Least sunny months in Niimi: January, February and December receive an average of 6 hours 13 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Niimi. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours162206249272287274263290236228221197
Mean daily daylight hours10h 4m10h 54m11h 58m13h 4m13h 59m14h 27m14h 13m13h 24m12h 22m11h 16m10h 19m9h 50m

Solar UV radiation in Niimi, Japan

Niimi experiences the highest level of ultraviolet (UV) radiation in May, July and August, when the maximum UV index can reach values of 11 - 12, which corresponds to the Extreme category of sun exposure. January, November and December are in the Moderate exposure category. In these months, the maximum values of the UV index do not exceed 5. For more detailed information, check out our hourly Niimi UV Index data.

Average daily maximum UV levels by month for Niimi. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)468101111121210753