Innoshima climate — normals and trends
Innoshima (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 16.6 °C and it receives 1,346 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 (27.6 °C on average) and the coldest is January (6.7 °C). Rainfall peaks in June.
Innoshima averages 1 frost days, 19 hot days (≥ 30 °C) and 136 rainy days per year.
Innoshima has warmed by +1.5 °C between 1940 and 2025, or +0.17 °C per decade. This trend is statistically significant.
The number of frost days there went from about 2 to 0 per year over the period.
The hottest day of the period reached 34.3 °C (on 30 July 2004) and the coldest -3.8 °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
InnoshimaHiroshima
- coords
- 34.28°, 133.18°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
16.6°C
Average daily high
18.8°C
Average daily low
14.4°C
Annual rainfall
1,346mm
Sunshine / day
8.9h
Mean relative humidity
71%
Average peak wind
19.5km/h
Seasonal range
20.9°C
Frost days (< 0 °C)
1 d/yr
Hot days (≥ 30 °C)
19 d/yr
Rainy days (≥ 1 mm)
136 d/yr
Annual snowfall
5.6 cm
Average feels-like high
18.5 °C
Average feels-like low
13.3 °C
Average peak gust
34.1 km/h
Tropical nights (≥ 20 °C)
107 d/yr
Solar radiation
14.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.5 °C
since 1940
+0.2 °C per decade · r² = 0.59 · 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
34.3 °C
30 July 2004
Coldest day
-3.8 °C
26 February 1981
Wettest day
133 mm
7 July 2018
Windiest day
74.9 km/h
7 September 2004
Strongest gust
141.5 km/h
7 September 2004
Hottest feels-like
41.5 °C
25 July 2018
Coldest feels-like
-11.7 °C
26 February 1981
Snowiest day
10.9 cm
15 February 1968
Sunniest day
14.0 h
30 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 | 9.3 °C | +0.4 °C | 34 mm | -31 mm |
| Feb | 7.8 °C | -1.6 °C | 52 mm | -21 mm |
| Mar | 12.5 °C | +0.2 °C | 115 mm | +20 mm |
| Apr | 17.0 °C | +0.1 °C | 56 mm | -58 mm |
| May | 20.4 °C | -0.3 °C | 176 mm | +43 mm |
| Jun | 25.0 °C | +1.1 °C | 267 mm | +73 mm |
| Jul | 30.4 °C | +2.7 °C | 44 mm | -116 mm |
| Aug | 30.8 °C | +1.3 °C | 127 mm | +23 mm |
| Sep | 28.6 °C | +2.1 °C | 171 mm | +14 mm |
| Oct | 23.2 °C | +1.8 °C | 160 mm | +50 mm |
| Nov | 16.9 °C | +0.5 °C | 33 mm | -43 mm |
| Dec | 12.4 °C | +0.9 °C | 46 mm | -17 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 Innoshima?
Innoshima has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 16.6 °C and it receives 1,346 mm of precipitation per year.
What is the hottest day ever recorded in Innoshima?
The hottest day measured in Innoshima between 1940 and 2025 was 30 July 2004, reaching 34.3 °C.
What is the coldest day in Innoshima?
The coldest day measured in Innoshima between 1940 and 2025 was 26 February 1981, at -3.8 °C.
Does it snow in Innoshima?
Yes. Innoshima gets on average 5.6 cm of snow per year and has around 1 frost days.
Has the climate of Innoshima warmed?
Yes: Innoshima warmed by +1.5 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Innoshima?
The wettest day measured in Innoshima between 1940 and 2025 was 7 July 2018, with 133 mm of rain in 24 hours.
What was the windiest day in Innoshima?
The windiest day measured in Innoshima between 1940 and 2025 was 7 September 2004, with winds reaching 74.9 km/h.
What is the warmest month in Innoshima?
The warmest month in Innoshima is August (27.6 °C on average); the coldest is January (6.7 °C).
How much does it rain in Innoshima?
Innoshima receives on average 1,346 mm of precipitation per year, spread over about 136 rainy days.
Is it sunny in Innoshima?
Innoshima 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 Innoshima?
The heaviest 24-hour snowfall measured in Innoshima between 1940 and 2025 was 15 February 1968, with 10.9 cm.
Are there tropical nights in Innoshima?
Yes: Innoshima has on average 107 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Innoshima?
In Innoshima, between 1940 and 2025, the highest apparent temperature reached 41.5 °C on 25 July 2018, and the lowest was -11.7 °C on 26 February 1981.
Compare Innoshima with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Innoshima