nomadseason

Monthly climate in Nagano, Japan

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Nagano features a humid continental climate (Dfb). Temperatures typically range between -2 °C (29 °F) and 24 °C (75 °F) through the year, but rarely can drop to -15 °C (6 °F) or can rise to as high as 35 °C (95 °F). The average annual precipitation amounts to about 2073 mm (81.6 inches) and receives 228 rainy days on the 1 mm (0.04 inches) threshold annually. Nagano enjoys an average of 2960 hours of sunshine throughout the year, and daylight varies from 9 hours 40 minutes to 14 hours 37 minutes per day.

Monthly average temperatures in Nagano, Japan

The warmest months in Nagano are July, August and September, with daily mean temperatures ranging from 19 to 24 °C (67 - 75 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from -2 to 1 °C (29 - 34 °F) throughout the day. On average each year, Nagano experiences 57 days above 25 °C (77.0 °F) and 109 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Nagano. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum10°C
(51°F)		16°C
(61°F)		21°C
(70°F)		27°C
(81°F)		31°C
(88°F)		30°C
(87°F)		33°C
(91°F)		35°C
(95°F)		32°C
(89°F)		28°C
(82°F)		21°C
(70°F)		19°C
(66°F)
Mean maximum8°C
(47°F)		11°C
(52°F)		18°C
(64°F)		23°C
(73°F)		28°C
(83°F)		27°C
(81°F)		31°C
(88°F)		33°C
(91°F)		28°C
(83°F)		26°C
(79°F)		19°C
(66°F)		13°C
(55°F)
Average high2°C
(36°F)		3°C
(38°F)		9°C
(48°F)		14°C
(58°F)		21°C
(69°F)		23°C
(74°F)		26°C
(80°F)		28°C
(83°F)		24°C
(75°F)		18°C
(64°F)		12°C
(54°F)		5°C
(42°F)
Daily mean-2°C
(29°F)		-1°C
(30°F)		4°C
(39°F)		9°C
(48°F)		15°C
(59°F)		18°C
(65°F)		22°C
(73°F)		24°C
(75°F)		19°C
(67°F)		13°C
(56°F)		7°C
(44°F)		1°C
(34°F)
Average low-5°C
(23°F)		-5°C
(24°F)		-1°C
(30°F)		3°C
(38°F)		10°C
(49°F)		14°C
(57°F)		19°C
(67°F)		20°C
(69°F)		16°C
(60°F)		9°C
(49°F)		2°C
(37°F)		-3°C
(27°F)
Mean minimum-12°C
(11°F)		-10°C
(13°F)		-7°C
(20°F)		-3°C
(26°F)		2°C
(35°F)		9°C
(49°F)		16°C
(61°F)		16°C
(60°F)		10°C
(50°F)		3°C
(38°F)		-4°C
(25°F)		-9°C
(16°F)
Minimum-15°C
(6°F)		-14°C
(7°F)		-9°C
(16°F)		-5°C
(22°F)		0°C
(33°F)		5°C
(41°F)		15°C
(60°F)		11°C
(52°F)		7°C
(44°F)		2°C
(36°F)		-8°C
(19°F)		-10°C
(14°F)

Compare climate in Nagano with other places

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

Monthly average precipitation in Nagano, Japan

Nagano usually has the most precipitation in July, August and October, with an average of 22 rainy days and 252 mm (9.9 inches) of precipitation per month. The driest months in Nagano are February, March and November. On average, 119 mm (4.7 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Nagano. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)144 (5.7)129 (5.1)133 (5.2)141 (5.5)160 (6.3)171 (6.7)341 (13.4)198 (7.8)194 (7.6)217 (8.5)94 (3.7)151 (6.0)
Average precipitation days (≥ 1 mm)211918161618252319181520

Monthly sunshine hours in Nagano, Japan

The sunniest months in Nagano are May, June and August, when the sun shines an average of 9 hours 26 minutes a day. Least sunny months in Nagano: January, October and December receive an average of 6 hours 26 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Nagano. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours174224261278299279261289242216223208
Mean daily daylight hours9h 56m10h 49m11h 57m13h 8m14h 7m14h 37m14h 22m13h 30m12h 23m11h 13m10h 11m9h 40m

Solar UV radiation in Nagano, Japan

Nagano experiences the highest level of ultraviolet (UV) radiation in May, July and August, when the maximum UV index can reach values of 11 - 11, 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 Nagano UV Index data.

Average daily maximum UV levels by month for Nagano. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)46991111111110753