Okayama climate — normals and trends
Okayama (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 15.8 °C and it receives 1,278 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is August (27.8 °C on average) and the coldest is January (4.7 °C). Rainfall peaks in June.
Okayama averages 37 frost days, 50 hot days (≥ 30 °C) and 113 rainy days per year.
Okayama has warmed by +2.9 °C between 1940 and 2025, or +0.34 °C per decade. This trend is statistically significant.
The number of frost days there went from about 58 to 16 per year over the period.
The hottest day of the period reached 39.2 °C (on 4 August 2001) and the coldest -8.0 °C (on 27 January 1981).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
OkayamaOkayama
- coords
- 34.65°, 133.93°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
15.8°C
Average daily high
20.1°C
Average daily low
11.5°C
Annual rainfall
1,278mm
Sunshine / day
9.0h
Mean relative humidity
71%
Average peak wind
14.8km/h
Seasonal range
23.1°C
Frost days (< 0 °C)
37 d/yr
Hot days (≥ 30 °C)
50 d/yr
Rainy days (≥ 1 mm)
113 d/yr
Annual snowfall
4.8 cm
Average feels-like high
19.8 °C
Average feels-like low
10.8 °C
Average peak gust
34.7 km/h
Tropical nights (≥ 20 °C)
87 d/yr
Solar radiation
15.3 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.9 °C
since 1940
+0.3 °C per decade · r² = 0.72 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
39.2 °C
4 August 2001
Coldest day
-8.0 °C
27 January 1981
Wettest day
162 mm
2 July 1952
Windiest day
65.6 km/h
29 August 1960
Strongest gust
162.0 km/h
4 September 1993
Hottest feels-like
44.7 °C
4 August 2001
Coldest feels-like
-12.7 °C
16 February 1977
Snowiest day
20.9 cm
15 February 1968
Sunniest day
14.0 h
20 May 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 9.6 °C | +0.6 °C | 11 mm | -26 mm |
| Feb | 8.4 °C | -1.4 °C | 27 mm | -24 mm |
| Mar | 14.3 °C | +0.9 °C | 96 mm | +11 mm |
| Apr | 20.3 °C | +1.4 °C | 53 mm | -57 mm |
| May | 23.4 °C | +0.3 °C | 167 mm | +40 mm |
| Jun | 28.2 °C | +2.0 °C | 217 mm | +30 mm |
| Jul | 33.5 °C | +3.4 °C | 85 mm | -102 mm |
| Aug | 34.7 °C | +3.0 °C | 131 mm | +10 mm |
| Sep | 30.6 °C | +2.7 °C | 188 mm | +17 mm |
| Oct | 24.0 °C | +1.7 °C | 167 mm | +63 mm |
| Nov | 17.4 °C | +0.6 °C | 26 mm | -36 mm |
| Dec | 12.3 °C | +0.8 °C | 31 mm | -4 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Okayama?
Okayama has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 15.8 °C and it receives 1,278 mm of precipitation per year.
What is the hottest day ever recorded in Okayama?
The hottest day measured in Okayama between 1940 and 2025 was 4 August 2001, reaching 39.2 °C.
What is the coldest day in Okayama?
The coldest day measured in Okayama between 1940 and 2025 was 27 January 1981, at -8.0 °C.
Does it snow in Okayama?
Yes. Okayama gets on average 4.8 cm of snow per year and has around 37 frost days.
Has the climate of Okayama warmed?
Yes: Okayama warmed by +2.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Okayama?
The wettest day measured in Okayama between 1940 and 2025 was 2 July 1952, with 162 mm of rain in 24 hours.
What was the windiest day in Okayama?
The windiest day measured in Okayama between 1940 and 2025 was 29 August 1960, with winds reaching 65.6 km/h.
What is the warmest month in Okayama?
The warmest month in Okayama is August (27.8 °C on average); the coldest is January (4.7 °C).
How much does it rain in Okayama?
Okayama receives on average 1,278 mm of precipitation per year, spread over about 113 rainy days.
Is it sunny in Okayama?
Okayama gets on average 9.0 hours of sunshine per day, roughly 3,285 hours per year over 1940-2025.
What is the biggest single-day snowfall in Okayama?
The heaviest 24-hour snowfall measured in Okayama between 1940 and 2025 was 15 February 1968, with 20.9 cm.
Are there tropical nights in Okayama?
Yes: Okayama has on average 87 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Okayama?
In Okayama, between 1940 and 2025, the highest apparent temperature reached 44.7 °C on 4 August 2001, and the lowest was -12.7 °C on 16 February 1977.
Compare Okayama with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Okayama