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Monthly climate in Saikai, Japan

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Saikai features a humid subtropical climate (Cfa). Temperatures typically range between 8 °C (47 °F) and 28 °C (82 °F) through the year, but rarely can drop to 0 °C (32 °F) or can rise to as high as 33 °C (91 °F). The average annual precipitation amounts to about 2058 mm (81.0 inches) and receives 129 rainy days on the 1 mm (0.04 inches) threshold annually. Saikai enjoys an average of 3048 hours of sunshine throughout the year, and daylight varies from 10 hours 0 minutes to 14 hours 16 minutes per day.

Monthly average temperatures in Saikai, Japan

The warmest months in Saikai are July, August and September, with daily mean temperatures ranging from 25 to 28 °C (77 - 82 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from 8 to 10 °C (47 - 51 °F) throughout the day. On average each year, Saikai experiences 82 days above 25 °C (77.0 °F) and 0 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Saikai. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum18°C
(65°F)		17°C
(62°F)		20°C
(68°F)		22°C
(72°F)		24°C
(76°F)		28°C
(83°F)		32°C
(90°F)		33°C
(91°F)		33°C
(91°F)		29°C
(84°F)		22°C
(72°F)		22°C
(71°F)
Mean maximum15°C
(60°F)		15°C
(60°F)		18°C
(65°F)		21°C
(69°F)		24°C
(75°F)		27°C
(80°F)		30°C
(87°F)		33°C
(91°F)		30°C
(86°F)		27°C
(81°F)		22°C
(72°F)		18°C
(64°F)
Average high10°C
(50°F)		11°C
(51°F)		14°C
(58°F)		17°C
(64°F)		21°C
(70°F)		24°C
(76°F)		28°C
(82°F)		29°C
(85°F)		27°C
(80°F)		22°C
(73°F)		17°C
(64°F)		12°C
(54°F)
Daily mean8°C
(47°F)		9°C
(48°F)		12°C
(54°F)		15°C
(60°F)		19°C
(67°F)		23°C
(73°F)		26°C
(79°F)		28°C
(82°F)		25°C
(77°F)		21°C
(69°F)		16°C
(60°F)		10°C
(51°F)
Average low7°C
(44°F)		7°C
(44°F)		10°C
(50°F)		14°C
(57°F)		18°C
(64°F)		21°C
(70°F)		25°C
(77°F)		26°C
(80°F)		23°C
(75°F)		19°C
(66°F)		14°C
(57°F)		9°C
(48°F)
Mean minimum3°C
(37°F)		2°C
(36°F)		6°C
(43°F)		9°C
(49°F)		14°C
(57°F)		19°C
(66°F)		22°C
(73°F)		24°C
(75°F)		20°C
(68°F)		15°C
(59°F)		9°C
(49°F)		4°C
(39°F)
Minimum-0°C
(32°F)		0°C
(33°F)		5°C
(42°F)		8°C
(46°F)		13°C
(56°F)		18°C
(65°F)		21°C
(70°F)		21°C
(70°F)		19°C
(67°F)		14°C
(57°F)		8°C
(47°F)		2°C
(36°F)

Compare climate in Saikai with other places

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

Monthly average precipitation in Saikai, Japan

Saikai usually has the most precipitation in June, July and August, with an average of 14 rainy days and 315 mm (12.4 inches) of precipitation per month. The driest months in Saikai are January, November and December. On average, 68 mm (2.7 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Saikai. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)58 (2.3)93 (3.6)147 (5.8)130 (5.1)206 (8.1)231 (9.1)393 (15.5)320 (12.6)223 (8.8)110 (4.3)65 (2.6)81 (3.2)
Average precipitation days (≥ 1 mm)8101181113171414797

Monthly sunshine hours in Saikai, Japan

The sunniest months in Saikai are May, July and August, when the sun shines an average of 9 hours 28 minutes a day. Least sunny months in Saikai: January, February and December receive an average of 6 hours 31 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Saikai. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours168226263284288273286306258258235198
Mean daily daylight hours10h 13m10h 59m11h 58m12h 59m13h 51m14h 16m14h 3m13h 18m12h 21m11h 20m10h 27m10h 0m

Solar UV radiation in Saikai, Japan

Saikai experiences the highest level of ultraviolet (UV) radiation in July, August and September, when the maximum UV index can reach values of 11 - 12, which corresponds to the Extreme category of sun exposure. January, February and December are in the Moderate / High exposure category. In these months, the maximum values of the UV index do not exceed 6. For more detailed information, check out our hourly Saikai UV Index data.

Average daily maximum UV levels by month for Saikai. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)468101111121211764