Okayama climate
Okayama is warmest in August, with average highs of 31 °C, and coldest in January, when nights average 1.1 °C. July is the wettest month (185 mm) and January the driest (41 mm). Figures are 1991–2020 climate normals.
Across a full year Okayama averages 1,266 mm of rain, 116 days above 25 °C and 28 days below freezing.
Japan · population 724,691 · 1991–2020 normals
Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month
- Warmest month August 31 °C
- Coldest month January 1.1 °C
- Driest month January 41 mm
- Wettest month July 185 mm
- Least cloud December 47 % cloud
- Hottest on record July 38 °C
- Coldest on record February -6.8 °C
What to expectOkayama through the year
Okayama has a clear annual cycle: average daily highs run from 8.8 °C in January to 31 °C in August, a swing of 23 °C in mean temperature across the year.
Counted across a normal year, 116 days a year reach 25 °C, 43 of them reach 30 °C, 28 nights drop below freezing. The warmest reading in the 1991–2020 record is 38 °C, in July.
Rain is strongly seasonal. July averages 185 mm against 41 mm in January — 4.6 times as much. Planning around the dry months matters more here than planning around temperature.
Month by month
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | 8.8 °C | 41 mm | 52 % |
| February | 9.8 °C | 51 mm | 56 % |
| March | 13.3 °C | 92 mm | 57 % |
| April | 18.5 °C | 109 mm | 58 % |
| May | 23.0 °C | 123 mm | 63 % |
| June | 26.1 °C | 178 mm | 76 % |
| July | 29.7 °C | 185 mm | 69 % |
| August | 31.2 °C | 108 mm | 59 % |
| September | 27.3 °C | 163 mm | 60 % |
| October | 21.8 °C | 113 mm | 51 % |
| November | 16.3 °C | 57 mm | 48 % |
| December | 11.0 °C | 47 mm | 47 % |
Temperature month by month
| Month | Avg high | Avg low | Mean | Record high | Record low | Days above 25 °C | Days above 30 °C | Days below 0 °C |
|---|---|---|---|---|---|---|---|---|
| January | 8.8 °C | 1.1 °C | 4.6 °C | 17.0 °C | -5.0 °C | 0 | 0 | 11 |
| February | 9.8 °C | 1.5 °C | 5.4 °C | 20.8 °C | -6.8 °C | 0 | 0 | 10 |
| March | 13.3 °C | 4.4 °C | 8.6 °C | 22.3 °C | -3.6 °C | 0 | 0 | 3 |
| April | 18.5 °C | 9.4 °C | 13.8 °C | 28.3 °C | -1.3 °C | 0 | 0 | 0 |
| May | 23.0 °C | 14.4 °C | 18.6 °C | 33.2 °C | 4.1 °C | 7 | 0 | 0 |
| June | 26.1 °C | 18.9 °C | 22.3 °C | 34.0 °C | 12.0 °C | 20 | 2 | 0 |
| July | 29.7 °C | 23.2 °C | 26.2 °C | 38.4 °C | 16.6 °C | 30 | 14 | 0 |
| August | 31.2 °C | 24.2 °C | 27.5 °C | 37.6 °C | 16.3 °C | 31 | 21 | 0 |
| September | 27.3 °C | 20.2 °C | 23.5 °C | 36.1 °C | 10.6 °C | 23 | 5 | 0 |
| October | 21.8 °C | 13.9 °C | 17.6 °C | 31.0 °C | 3.9 °C | 4 | 0 | 0 |
| November | 16.3 °C | 8.1 °C | 11.9 °C | 24.5 °C | -0.6 °C | 0 | 0 | 0 |
| December | 11.0 °C | 3.1 °C | 6.8 °C | 20.6 °C | -5.7 °C | 0 | 0 | 4 |
Rain, sun and wind month by month
| Month | Rainfall | Wet days | Daylight | Cloud cover | Humidity | Wind |
|---|---|---|---|---|---|---|
| January | 41 mm | 5 | 10 h/day | 52 % | 68 % | 18 km/h |
| February | 51 mm | 6 | 11 h/day | 56 % | 68 % | 17 km/h |
| March | 92 mm | 9 | 12 h/day | 57 % | 68 % | 17 km/h |
| April | 109 mm | 10 | 13 h/day | 58 % | 69 % | 16 km/h |
| May | 123 mm | 10 | 14 h/day | 63 % | 72 % | 15 km/h |
| June | 178 mm | 12 | 14 h/day | 76 % | 78 % | 14 km/h |
| July | 185 mm | 13 | 14 h/day | 69 % | 81 % | 14 km/h |
| August | 108 mm | 10 | 13 h/day | 59 % | 76 % | 14 km/h |
| September | 163 mm | 11 | 12 h/day | 60 % | 75 % | 14 km/h |
| October | 113 mm | 8 | 11 h/day | 51 % | 74 % | 14 km/h |
| November | 57 mm | 6 | 10 h/day | 48 % | 72 % | 14 km/h |
| December | 47 mm | 5 | 9.9 h/day | 47 % | 70 % | 17 km/h |
How Okayama compares
The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.
| Destination | Summer high | Winter low | Rain per year | Days above 25 °C |
|---|---|---|---|---|
| Okayama | 31 °C | 1.1 °C | 1,266 mm | 116 |
| Kurashiki · Japan | 31 °C | 2.5 °C | 1,297 mm | 112 |
| Takamatsu · Japan | 30 °C | 3.6 °C | 1,444 mm | 95 |
| Fukuyama · Japan | 31 °C | 2.1 °C | 1,257 mm | 114 |
| Himeji · Japan | 29 °C | 1.8 °C | 1,541 mm | 92 |
Planning a trip? See the best time to visit Okayama.
QuestionsCommon questions about Okayama’s climate
When is the best time to visit Okayama?
That depends on what you want, so the honest answer is a comparison rather than a single month. May, June, October sit closest to 20 °C on average, August is the warmest month and January the driest. The month-by-month table above has the full picture.
How hot does Okayama get?
In August, the warmest month, daily highs average 31 °C. About 43 days a year pass 30 °C. The highest value in the 1991–2020 record is 38 °C.
How cold does it get in winter?
Nights average 1.1 °C in January, the coldest month. A normal year has 28 nights below freezing.
Which month is wettest in Okayama?
July, averaging 185 mm over 13 days with rain. The driest month is January with 41 mm. The year as a whole averages 1,266 mm.
Are these figures a forecast?
No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Okayama rather than what any particular week will bring. Individual years can differ substantially from the normal.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.