Monthly climate in Oyama, Japan

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Oyama features a humid subtropical climate (Cfa). Temperatures typically range between 4 °C (39 °F) and 27 °C (82 °F) through the year, but rarely can drop to -10 °C (14 °F) or can rise to as high as 37 °C (98 °F). The average annual precipitation amounts to about 1620 mm (63.8 inches) and receives 151 rainy days on the 1 mm (0.04 inches) threshold annually. Oyama enjoys an average of 2899 hours of sunshine throughout the year, and daylight varies from 9 hours 44 minutes to 14 hours 33 minutes per day.

Monthly average temperatures in Oyama, Japan

The warmest months in Oyama are July, August and September, with daily mean temperatures ranging from 23 to 27 °C (74 - 82 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from 4 to 6 °C (39 - 43 °F) throughout the day. On average each year, Oyama experiences 97 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 Oyama. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum16°C
(62°F)
21°C
(70°F)
24°C
(75°F)
29°C
(84°F)
33°C
(92°F)
33°C
(92°F)
36°C
(97°F)
37°C
(98°F)
35°C
(95°F)
32°C
(89°F)
23°C
(74°F)
20°C
(67°F)
Mean maximum15°C
(59°F)
17°C
(63°F)
22°C
(72°F)
26°C
(79°F)
31°C
(87°F)
30°C
(86°F)
34°C
(93°F)
36°C
(96°F)
33°C
(92°F)
29°C
(84°F)
22°C
(72°F)
17°C
(64°F)
Average high9°C
(48°F)
10°C
(51°F)
14°C
(58°F)
19°C
(66°F)
24°C
(75°F)
26°C
(79°F)
29°C
(85°F)
31°C
(89°F)
27°C
(80°F)
21°C
(71°F)
17°C
(62°F)
11°C
(52°F)
Daily mean4°C
(39°F)
5°C
(41°F)
9°C
(49°F)
14°C
(57°F)
19°C
(66°F)
22°C
(72°F)
26°C
(78°F)
27°C
(82°F)
23°C
(74°F)
18°C
(64°F)
12°C
(53°F)
6°C
(43°F)
Average low-1°C
(31°F)
0°C
(33°F)
4°C
(40°F)
9°C
(48°F)
14°C
(58°F)
18°C
(65°F)
23°C
(73°F)
24°C
(76°F)
20°C
(68°F)
14°C
(58°F)
7°C
(45°F)
2°C
(35°F)
Mean minimum-5°C
(23°F)
-4°C
(25°F)
-2°C
(28°F)
2°C
(36°F)
7°C
(44°F)
15°C
(58°F)
19°C
(66°F)
19°C
(67°F)
15°C
(58°F)
8°C
(46°F)
1°C
(34°F)
-3°C
(27°F)
Minimum-10°C
(14°F)
-6°C
(22°F)
-4°C
(25°F)
-0°C
(32°F)
5°C
(41°F)
12°C
(54°F)
17°C
(63°F)
16°C
(61°F)
13°C
(55°F)
5°C
(41°F)
-2°C
(29°F)
-4°C
(26°F)

Compare climate in Oyama with other places

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

Monthly average precipitation in Oyama, Japan

Oyama usually has the most precipitation in July, September and October, with an average of 19 rainy days and 237 mm (9.3 inches) of precipitation per month. The driest months in Oyama are January, February and December. On average, 43 mm (1.7 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Oyama. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)38 (1.5)41 (1.6)131 (5.2)129 (5.1)137 (5.4)160 (6.3)258 (10.2)156 (6.1)195 (7.7)258 (10.1)67 (2.6)50 (2.0)
Average precipitation days (≥ 1 mm)46111213172117201686

Monthly sunshine hours in Oyama, Japan

The sunniest months in Oyama are April, May and August, when the sun shines an average of 8 hours 57 minutes a day. Least sunny months in Oyama: January, September and October receive an average of 6 hours 44 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Oyama. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours190238263276278261227269224206231231
Mean daily daylight hours9h 59m10h 51m11h 57m13h 6m14h 4m14h 33m14h 19m13h 28m12h 22m11h 14m10h 14m9h 44m

Solar UV radiation in Oyama, Japan

Oyama experiences the highest level of ultraviolet (UV) radiation in June, 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 Oyama UV Index data.

Average daily maximum UV levels by month for Oyama. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)3579101111109653