Ishii climate — normals and trends
Ishii (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 15.5 °C and it receives 2,043 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 (26.1 °C on average) and the coldest is January (5.4 °C). Rainfall peaks in September.
Ishii averages 8 frost days, 12 hot days (≥ 30 °C) and 151 rainy days per year.
Ishii has warmed by +2.0 °C between 1940 and 2025, or +0.23 °C per decade. This trend is statistically significant.
The number of frost days there went from about 15 to 1 per year over the period.
The hottest day of the period reached 33.5 °C (on 30 July 2024) and the coldest -6.0 °C (on 26 February 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
IshiiTokushima
- coords
- 34.07°, 134.44°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
15.5°C
Average daily high
18.3°C
Average daily low
12.8°C
Annual rainfall
2,043mm
Sunshine / day
8.9h
Mean relative humidity
73%
Average peak wind
18.3km/h
Seasonal range
20.7°C
Frost days (< 0 °C)
8 d/yr
Hot days (≥ 30 °C)
12 d/yr
Rainy days (≥ 1 mm)
151 d/yr
Annual snowfall
8.6 cm
Average feels-like high
18.0 °C
Average feels-like low
11.4 °C
Average peak gust
41.3 km/h
Tropical nights (≥ 20 °C)
91 d/yr
Solar radiation
14.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.0 °C
since 1940
+0.2 °C per decade · r² = 0.66 · 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
33.5 °C
30 July 2024
Coldest day
-6.0 °C
26 February 1981
Wettest day
242 mm
19 September 1990
Windiest day
78.8 km/h
26 September 1959
Strongest gust
182.5 km/h
17 September 1945
Hottest feels-like
40.6 °C
16 August 1998
Coldest feels-like
-13.5 °C
26 February 1981
Snowiest day
28.8 cm
15 February 1968
Sunniest day
14.0 h
28 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 | 8.6 °C | +0.3 °C | 32 mm | -31 mm |
| Feb | 7.5 °C | -1.4 °C | 28 mm | -52 mm |
| Mar | 12.9 °C | +0.7 °C | 116 mm | -4 mm |
| Apr | 17.7 °C | +0.7 °C | 97 mm | -64 mm |
| May | 21.0 °C | +0.4 °C | 280 mm | +87 mm |
| Jun | 25.6 °C | +2.0 °C | 243 mm | -44 mm |
| Jul | 29.7 °C | +2.2 °C | 74 mm | -181 mm |
| Aug | 30.6 °C | +2.0 °C | 168 mm | -38 mm |
| Sep | 28.3 °C | +2.7 °C | 176 mm | -116 mm |
| Oct | 22.5 °C | +2.0 °C | 292 mm | +86 mm |
| Nov | 16.5 °C | +0.7 °C | 36 mm | -79 mm |
| Dec | 12.3 °C | +1.4 °C | 48 mm | -16 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 Ishii?
Ishii has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 15.5 °C and it receives 2,043 mm of precipitation per year.
What is the hottest day ever recorded in Ishii?
The hottest day measured in Ishii between 1940 and 2025 was 30 July 2024, reaching 33.5 °C.
What is the coldest day in Ishii?
The coldest day measured in Ishii between 1940 and 2025 was 26 February 1981, at -6.0 °C.
Does it snow in Ishii?
Yes. Ishii gets on average 8.6 cm of snow per year and has around 8 frost days.
Has the climate of Ishii warmed?
Yes: Ishii warmed by +2.0 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Ishii?
The wettest day measured in Ishii between 1940 and 2025 was 19 September 1990, with 242 mm of rain in 24 hours.
What was the windiest day in Ishii?
The windiest day measured in Ishii between 1940 and 2025 was 26 September 1959, with winds reaching 78.8 km/h.
What is the warmest month in Ishii?
The warmest month in Ishii is August (26.1 °C on average); the coldest is January (5.4 °C).
How much does it rain in Ishii?
Ishii receives on average 2,043 mm of precipitation per year, spread over about 151 rainy days.
Is it sunny in Ishii?
Ishii gets on average 8.9 hours of sunshine per day, roughly 3,249 hours per year over 1940-2025.
What is the biggest single-day snowfall in Ishii?
The heaviest 24-hour snowfall measured in Ishii between 1940 and 2025 was 15 February 1968, with 28.8 cm.
Are there tropical nights in Ishii?
Yes: Ishii has on average 91 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Ishii?
In Ishii, between 1940 and 2025, the highest apparent temperature reached 40.6 °C on 16 August 1998, and the lowest was -13.5 °C on 26 February 1981.
Compare Ishii with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Ishii