Kōshi climate — normals and trends
Kōshi (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 15.3 °C and it receives 1,876 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 (26.4 °C on average) and the coldest is January (4.4 °C). Rainfall peaks in June.
Kōshi averages 37 frost days, 37 hot days (≥ 30 °C) and 143 rainy days per year.
Kōshi has warmed by +2.7 °C between 1940 and 2025, or +0.32 °C per decade. This trend is statistically significant.
The number of frost days there went from about 57 to 17 per year over the period.
The hottest day of the period reached 36.4 °C (on 17 July 1994) and the coldest -15.4 °C (on 19 February 1977).
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
KōshiKumamoto
- coords
- 32.89°, 130.78°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
15.3°C
Average daily high
19.6°C
Average daily low
11.4°C
Annual rainfall
1,876mm
Sunshine / day
8.1h
Mean relative humidity
75%
Average peak wind
12.2km/h
Seasonal range
22.0°C
Frost days (< 0 °C)
37 d/yr
Hot days (≥ 30 °C)
37 d/yr
Rainy days (≥ 1 mm)
143 d/yr
Annual snowfall
7.9 cm
Average feels-like high
19.8 °C
Average feels-like low
10.8 °C
Average peak gust
32.9 km/h
Tropical nights (≥ 20 °C)
85 d/yr
Solar radiation
13.9 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.7 °C
since 1940
+0.3 °C per decade · r² = 0.76 · 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
36.4 °C
17 July 1994
Coldest day
-15.4 °C
19 February 1977
Wettest day
215 mm
6 July 2018
Windiest day
63.4 km/h
27 September 1991
Strongest gust
169.2 km/h
27 September 1991
Hottest feels-like
42.7 °C
3 August 2024
Coldest feels-like
-19.7 °C
19 February 1977
Snowiest day
16.9 cm
15 February 1968
Sunniest day
13.8 h
2 June 1942
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 | 9.0 °C | +0.6 °C | 21 mm | -40 mm |
| Feb | 8.2 °C | -1.5 °C | 53 mm | -35 mm |
| Mar | 14.9 °C | +1.3 °C | 160 mm | +31 mm |
| Apr | 19.9 °C | +0.9 °C | 103 mm | -55 mm |
| May | 23.0 °C | +0.1 °C | 319 mm | +128 mm |
| Jun | 26.9 °C | +1.5 °C | 438 mm | +63 mm |
| Jul | 32.6 °C | +3.7 °C | 60 mm | -260 mm |
| Aug | 31.4 °C | +1.1 °C | 287 mm | +118 mm |
| Sep | 29.6 °C | +2.4 °C | 152 mm | -6 mm |
| Oct | 25.4 °C | +3.1 °C | 62 mm | -29 mm |
| Nov | 17.7 °C | +1.1 °C | 31 mm | -44 mm |
| Dec | 12.9 °C | +2.1 °C | 50 mm | -9 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 Kōshi?
Kōshi has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 15.3 °C and it receives 1,876 mm of precipitation per year.
What is the hottest day ever recorded in Kōshi?
The hottest day measured in Kōshi between 1940 and 2025 was 17 July 1994, reaching 36.4 °C.
What is the coldest day in Kōshi?
The coldest day measured in Kōshi between 1940 and 2025 was 19 February 1977, at -15.4 °C.
Does it snow in Kōshi?
Yes. Kōshi gets on average 7.9 cm of snow per year and has around 37 frost days.
Has the climate of Kōshi warmed?
Yes: Kōshi warmed by +2.7 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Kōshi?
The wettest day measured in Kōshi between 1940 and 2025 was 6 July 2018, with 215 mm of rain in 24 hours.
What was the windiest day in Kōshi?
The windiest day measured in Kōshi between 1940 and 2025 was 27 September 1991, with winds reaching 63.4 km/h.
What is the warmest month in Kōshi?
The warmest month in Kōshi is August (26.4 °C on average); the coldest is January (4.4 °C).
How much does it rain in Kōshi?
Kōshi receives on average 1,876 mm of precipitation per year, spread over about 143 rainy days.
Is it sunny in Kōshi?
Kōshi gets on average 8.1 hours of sunshine per day, roughly 2,957 hours per year over 1940-2025.
What is the biggest single-day snowfall in Kōshi?
The heaviest 24-hour snowfall measured in Kōshi between 1940 and 2025 was 15 February 1968, with 16.9 cm.
Are there tropical nights in Kōshi?
Yes: Kōshi has on average 85 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Kōshi?
In Kōshi, between 1940 and 2025, the highest apparent temperature reached 42.7 °C on 3 August 2024, and the lowest was -19.7 °C on 19 February 1977.
Compare Kōshi with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Kōshi