Okayama climate
Okayama (Japan) has a humid subtropical climate (Köppen Cfa). The average temperature over the year is 16 °C61 °F, and about 1,466 mm58 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Okayama climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | 948 | 235 | 541 | 542.1 | 8 |
| Feb | 1050 | 236 | 643 | 682.7 | 7 |
| Mar | 1457 | 540 | 948 | 963.8 | 2 |
| Apr | 1966 | 948 | 1457 | 1064.2 | 0 |
| May | 2374 | 1457 | 1966 | 1325.2 | 0 |
| Jun | 2780 | 1966 | 2373 | 1957.7 | 0 |
| Jul | 3086 | 2474 | 2780 | 2198.6 | 0 |
| Aug | 3188 | 2576 | 2882 | 1385.4 | 0 |
| Sep | 2882 | 2170 | 2476 | 1877.4 | 0 |
| Oct | 2272 | 1559 | 1966 | 1305.1 | 0 |
| Nov | 1762 | 948 | 1355 | 702.8 | 0 |
| Dec | 1152 | 439 | 745 | 702.8 | 2 |
| Year | 3188 | 235 | 1661 | 1,46658 | 19 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 79% | 72% | 2.3 | 10:04 |
| Feb | 78% | 71% | 3.0 | 10:53 |
| Mar | 76% | 65% | 4.0 | 11:53 |
| Apr | 76% | 64% | 4.9 | 13:01 |
| May | 77% | 67% | 5.4 | 13:58 |
| Jun | 81% | 79% | 4.9 | 14:28 |
| Jul | 84% | 72% | 5.1 | 14:16 |
| Aug | 80% | 64% | 5.3 | 13:27 |
| Sep | 80% | 70% | 4.2 | 12:20 |
| Oct | 79% | 62% | 3.5 | 11:15 |
| Nov | 79% | 62% | 2.6 | 10:18 |
| Dec | 79% | 69% | 2.1 | 9:51 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Okayama is like
The warmest month is August, with an average high of 31 °C88 °F and a low of 25 °C76 °F. The coldest is January, when highs average 9 °C48 °F and lows 2 °C35 °F. Seasons are strongly marked: the warmest month is on average 22.7 °C40.9 °F warmer than the coldest.
It is wet, with about 1,466 mm58 in of precipitation per year. The wettest three-month stretch is June–August, which brings 38% of the annual total. The wettest month is July (219 mm8.6 in), the driest is January (54 mm2.1 in).
Relative humidity ranges from 76% in April to 84% in July. The clearest skies (lowest average cloud amount, 62%) are typical of October. Average wind speed near the ground ranges from 7 km/h (4 mph) in June to 12 km/h (7 mph) in January. Daylight lasts from about 9.8 hours in December to 14.5 hours in June.
Best time to visit Okayama
Based on these averages, the most comfortable months for sightseeing and outdoor activities are April and May and October and November: average highs of 17 °C62 °F to 23 °C74 °F with 70 mm2.8 in to 132 mm5.2 in of precipitation per month.
The most challenging month is July, which is very wet (219 mm8.6 in) and humid (84% relative humidity).
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Okayama
- Winter (December–February) — highs 948 to 11 °C52 °F, lows 235 to 4 °C39 °F, about 64 mm2.5 in of precipitation a month. Pack a warm coat, layers and closed shoes.
- Spring (March–May) — highs 1457 to 23 °C74 °F, lows 540 to 14 °C57 °F, about 111 mm4.4 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an umbrella or light rain jacket.
- Summer (June–August) — highs 2780 to 31 °C88 °F, lows 1966 to 25 °C76 °F, about 184 mm7.2 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an umbrella or light rain jacket.
- Autumn (September–November) — highs 1762 to 28 °C82 °F, lows 948 to 21 °C70 °F, about 129 mm5.1 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an umbrella or light rain jacket.
How Okayama compares
Compared with Kobe, about 114 km to the east, Okayama is on average 0.4 °C0.8 °F cooler and receives a similar amount of precipitation. The difference is largest in December (1.6 °C2.9 °F cooler).
Of the 111 places in Japan covered by World Climates, Okayama is the 34th warmest by annual mean temperature and the 85th wettest by annual precipitation. See all of them on the Japan climate page.
Places in other countries with the most similar temperature and rainfall pattern: Chongming (China, Cfa), Kunshan (China, Cfa) and Baoshan (China, Cfa).
The same NASA POWER grid cell also contains Kurashiki (pop. 483,576) and Marugame (pop. 109,513). Their long-term averages in this dataset are essentially the same as for Okayama, so they do not have separate pages.
Nearby places
- Takamatsu 37 km · 16 °C61 °F · 1,466 mm58 in
- Tsuyama 45 km · 14 °C58 °F · 1,488 mm59 in
- Fukuyama 55 km · 16 °C61 °F · 1,526 mm60 in
- Himeji 72 km · 15 °C59 °F · 1,553 mm61 in
- Tokushima 87 km · 16 °C61 °F · 1,816 mm71 in
- Niihama 96 km · 17 °C62 °F · 1,699 mm67 in
- Tottori-shi 98 km · 16 °C60 °F · 1,806 mm71 in
- Imabari 107 km · 17 °C62 °F · 1,699 mm67 in
Frequently asked questions
What is the warmest month in Okayama?
August is the warmest month in Okayama, with an average high of 31 °C (88 °F) and an average low of 25 °C (76 °F).
What is the coldest month in Okayama?
January is the coldest month, with an average high of 9 °C (48 °F) and an average low of 2 °C (35 °F).
When does it rain the most in Okayama?
July is the wettest month with about 219 mm (8.6 in) of precipitation; January is the driest with about 54 mm (2.1 in).
What is the best time to visit Okayama?
Judging by long-term averages, the most comfortable months are April and May and October and November.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 98 m, while Okayama lies at about 5 m. Temperatures on this page were therefore adjusted by +0.6 °C1.1 °F using the standard lapse rate of 6.5 °C per 1,000 m.