nomadseason

Monthly climate in Itoigawa, Japan

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Itoigawa features a humid subtropical climate (Cfa). Temperatures typically range between 2 °C (35 °F) and 26 °C (78 °F) through the year, but rarely can drop to -6 °C (22 °F) or can rise to as high as 34 °C (94 °F). The average annual precipitation amounts to about 2768 mm (109.0 inches) and receives 231 rainy days on the 1 mm (0.04 inches) threshold annually. Itoigawa enjoys an average of 2967 hours of sunshine throughout the year, and daylight varies from 9 hours 39 minutes to 14 hours 38 minutes per day.

Monthly average temperatures in Itoigawa, Japan

The warmest months in Itoigawa are July, August and September, with daily mean temperatures ranging from 22 to 26 °C (72 - 78 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from 2 to 4 °C (35 - 40 °F) throughout the day. On average each year, Itoigawa experiences 45 days above 25 °C (77.0 °F) and 44 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Itoigawa. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum11°C
(53°F)		12°C
(54°F)		16°C
(61°F)		21°C
(70°F)		26°C
(79°F)		26°C
(80°F)		34°C
(94°F)		33°C
(91°F)		32°C
(90°F)		28°C
(82°F)		22°C
(71°F)		18°C
(65°F)
Mean maximum8°C
(47°F)		9°C
(49°F)		14°C
(58°F)		19°C
(66°F)		23°C
(74°F)		24°C
(75°F)		30°C
(86°F)		32°C
(90°F)		29°C
(84°F)		25°C
(76°F)		19°C
(67°F)		13°C
(56°F)
Average high3°C
(38°F)		3°C
(39°F)		7°C
(46°F)		12°C
(54°F)		18°C
(64°F)		21°C
(70°F)		26°C
(78°F)		28°C
(82°F)		24°C
(75°F)		18°C
(65°F)		13°C
(55°F)		6°C
(44°F)
Daily mean2°C
(35°F)		2°C
(35°F)		5°C
(41°F)		9°C
(49°F)		15°C
(59°F)		19°C
(66°F)		24°C
(75°F)		26°C
(78°F)		22°C
(72°F)		16°C
(62°F)		11°C
(51°F)		4°C
(40°F)
Average low-0°C
(32°F)		-0°C
(32°F)		3°C
(37°F)		7°C
(45°F)		13°C
(55°F)		17°C
(63°F)		22°C
(72°F)		24°C
(75°F)		20°C
(68°F)		15°C
(58°F)		8°C
(47°F)		3°C
(37°F)
Mean minimum-3°C
(26°F)		-4°C
(26°F)		-2°C
(29°F)		1°C
(34°F)		7°C
(45°F)		13°C
(56°F)		19°C
(67°F)		20°C
(69°F)		15°C
(60°F)		9°C
(49°F)		2°C
(37°F)		-2°C
(28°F)
Minimum-5°C
(23°F)		-6°C
(22°F)		-4°C
(24°F)		-1°C
(31°F)		6°C
(42°F)		10°C
(51°F)		18°C
(64°F)		18°C
(64°F)		13°C
(56°F)		8°C
(47°F)		-0°C
(32°F)		-4°C
(26°F)

Compare climate in Itoigawa with other places

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

Monthly average precipitation in Itoigawa, Japan

Itoigawa usually has the most precipitation in July, August and December, with an average of 22 rainy days and 302 mm (11.9 inches) of precipitation per month. The driest months in Itoigawa are April, May and June. On average, 160 mm (6.3 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Itoigawa. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)263 (10.4)235 (9.2)175 (6.9)174 (6.9)138 (5.4)168 (6.6)347 (13.7)265 (10.4)265 (10.4)258 (10.2)185 (7.3)294 (11.6)
Average precipitation days (≥ 1 mm)232218151513232021181924

Monthly sunshine hours in Itoigawa, Japan

The sunniest months in Itoigawa are May, June and August, when the sun shines an average of 9 hours 48 minutes a day. Least sunny months in Itoigawa: January, February and December receive an average of 5 hours 59 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Itoigawa. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours148204258280303296286302252227215192
Mean daily daylight hours9h 55m10h 48m11h 57m13h 8m14h 8m14h 38m14h 23m13h 31m12h 23m11h 12m10h 10m9h 39m

Solar UV radiation in Itoigawa, Japan

Itoigawa experiences the highest level of ultraviolet (UV) radiation in May, July and August, when the maximum UV index can reach values of 10 - 11, which corresponds to the Very High / Extreme category of sun exposure. January, February 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 Itoigawa UV Index data.

Average daily maximum UV levels by month for Itoigawa. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)3579101011119653