Itogawa climate — normals and trends
Itogawa (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 15.8 °C and it receives 1,800 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 (5.9 °C). Rainfall peaks in June.
Itogawa averages 6 frost days, 15 hot days (≥ 30 °C) and 153 rainy days per year.
Itogawa has warmed by +2.1 °C between 1940 and 2025, or +0.24 °C per decade. This trend is statistically significant.
The number of frost days there went from about 12 to 0 per year over the period.
The hottest day of the period reached 34.1 °C (on 17 August 2002) and the coldest -5.4 °C (on 14 February 1942).
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
ItogawaWakayama
- coords
- 34.03°, 135.25°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
15.8°C
Average daily high
18.6°C
Average daily low
13.1°C
Annual rainfall
1,800mm
Sunshine / day
9.0h
Mean relative humidity
74%
Average peak wind
20.6km/h
Seasonal range
20.5°C
Frost days (< 0 °C)
6 d/yr
Hot days (≥ 30 °C)
15 d/yr
Rainy days (≥ 1 mm)
153 d/yr
Annual snowfall
14.0 cm
Average feels-like high
18.2 °C
Average feels-like low
11.5 °C
Average peak gust
42.3 km/h
Tropical nights (≥ 20 °C)
94 d/yr
Solar radiation
15.1 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.1 °C
since 1940
+0.2 °C per decade · r² = 0.67 · 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
34.1 °C
17 August 2002
Coldest day
-5.4 °C
14 February 1942
Wettest day
205 mm
19 July 1964
Windiest day
77.5 km/h
26 September 1959
Strongest gust
176.4 km/h
26 September 1959
Hottest feels-like
40.1 °C
3 August 2024
Coldest feels-like
-12.2 °C
17 February 1977
Snowiest day
10.5 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 | 8.9 °C | +0.4 °C | 47 mm | -36 mm |
| Feb | 7.6 °C | -1.4 °C | 49 mm | -45 mm |
| Mar | 13.6 °C | +1.3 °C | 99 mm | -27 mm |
| Apr | 17.8 °C | +0.6 °C | 88 mm | -58 mm |
| May | 21.3 °C | +0.3 °C | 255 mm | +83 mm |
| Jun | 25.8 °C | +1.8 °C | 211 mm | -54 mm |
| Jul | 30.3 °C | +2.7 °C | 129 mm | -86 mm |
| Aug | 30.5 °C | +1.4 °C | 166 mm | +21 mm |
| Sep | 28.7 °C | +2.4 °C | 155 mm | -49 mm |
| Oct | 23.1 °C | +1.9 °C | 266 mm | +101 mm |
| Nov | 16.6 °C | +0.4 °C | 50 mm | -57 mm |
| Dec | 12.6 °C | +1.5 °C | 73 mm | -7 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 Itogawa?
Itogawa has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 15.8 °C and it receives 1,800 mm of precipitation per year.
What is the hottest day ever recorded in Itogawa?
The hottest day measured in Itogawa between 1940 and 2025 was 17 August 2002, reaching 34.1 °C.
What is the coldest day in Itogawa?
The coldest day measured in Itogawa between 1940 and 2025 was 14 February 1942, at -5.4 °C.
Does it snow in Itogawa?
Yes. Itogawa gets on average 14.0 cm of snow per year and has around 6 frost days.
Has the climate of Itogawa warmed?
Yes: Itogawa warmed by +2.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Itogawa?
The wettest day measured in Itogawa between 1940 and 2025 was 19 July 1964, with 205 mm of rain in 24 hours.
What was the windiest day in Itogawa?
The windiest day measured in Itogawa between 1940 and 2025 was 26 September 1959, with winds reaching 77.5 km/h.
What is the warmest month in Itogawa?
The warmest month in Itogawa is August (26.4 °C on average); the coldest is January (5.9 °C).
How much does it rain in Itogawa?
Itogawa receives on average 1,800 mm of precipitation per year, spread over about 153 rainy days.
Is it sunny in Itogawa?
Itogawa 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 Itogawa?
The heaviest 24-hour snowfall measured in Itogawa between 1940 and 2025 was 15 February 1968, with 10.5 cm.
Are there tropical nights in Itogawa?
Yes: Itogawa has on average 94 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Itogawa?
In Itogawa, between 1940 and 2025, the highest apparent temperature reached 40.1 °C on 3 August 2024, and the lowest was -12.2 °C on 17 February 1977.
Compare Itogawa with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Itogawa