Yamaguchi climate — normals and trends
Yamaguchi (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 15.1 °C and it receives 1,650 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 (26.7 °C on average) and the coldest is January (4.2 °C). Rainfall peaks in July.
Yamaguchi averages 31 frost days, 41 hot days (≥ 30 °C) and 143 rainy days per year.
Yamaguchi has warmed by +2.8 °C between 1940 and 2025, or +0.33 °C per decade. This trend is statistically significant.
The number of frost days there went from about 53 to 9 per year over the period.
The hottest day of the period reached 37.7 °C (on 6 August 2021) and the coldest -9.9 °C (on 24 February 1975).
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
YamaguchiYamaguchi
- coords
- 34.18°, 131.47°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
15.1°C
Average daily high
19.3°C
Average daily low
11.2°C
Annual rainfall
1,650mm
Sunshine / day
8.7h
Mean relative humidity
74%
Average peak wind
14.7km/h
Seasonal range
22.5°C
Frost days (< 0 °C)
31 d/yr
Hot days (≥ 30 °C)
41 d/yr
Rainy days (≥ 1 mm)
143 d/yr
Annual snowfall
15.4 cm
Average feels-like high
19.1 °C
Average feels-like low
10.4 °C
Average peak gust
39.2 km/h
Tropical nights (≥ 20 °C)
78 d/yr
Solar radiation
14.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.8 °C
since 1940
+0.3 °C per decade · r² = 0.74 · 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
37.7 °C
6 August 2021
Coldest day
-9.9 °C
24 February 1975
Wettest day
192 mm
6 September 2005
Windiest day
63.6 km/h
7 September 2004
Strongest gust
194.4 km/h
7 September 2004
Hottest feels-like
44.2 °C
26 July 2018
Coldest feels-like
-14.6 °C
16 February 1977
Snowiest day
25.5 cm
15 February 1968
Sunniest day
13.9 h
8 June 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 | 8.5 °C | +0.7 °C | 28 mm | -32 mm |
| Feb | 7.0 °C | -1.9 °C | 55 mm | -19 mm |
| Mar | 14.3 °C | +1.5 °C | 143 mm | +35 mm |
| Apr | 19.3 °C | +1.0 °C | 86 mm | -52 mm |
| May | 22.4 °C | -0.2 °C | 233 mm | +80 mm |
| Jun | 27.5 °C | +1.9 °C | 279 mm | +25 mm |
| Jul | 33.0 °C | +3.7 °C | 79 mm | -194 mm |
| Aug | 32.3 °C | +1.4 °C | 262 mm | +89 mm |
| Sep | 29.5 °C | +2.4 °C | 196 mm | +4 mm |
| Oct | 24.1 °C | +2.2 °C | 85 mm | -10 mm |
| Nov | 17.2 °C | +0.9 °C | 33 mm | -41 mm |
| Dec | 11.8 °C | +1.3 °C | 62 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 Yamaguchi?
Yamaguchi has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 15.1 °C and it receives 1,650 mm of precipitation per year.
What is the hottest day ever recorded in Yamaguchi?
The hottest day measured in Yamaguchi between 1940 and 2025 was 6 August 2021, reaching 37.7 °C.
What is the coldest day in Yamaguchi?
The coldest day measured in Yamaguchi between 1940 and 2025 was 24 February 1975, at -9.9 °C.
Does it snow in Yamaguchi?
Yes. Yamaguchi gets on average 15.4 cm of snow per year and has around 31 frost days.
Has the climate of Yamaguchi warmed?
Yes: Yamaguchi warmed by +2.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Yamaguchi?
The wettest day measured in Yamaguchi between 1940 and 2025 was 6 September 2005, with 192 mm of rain in 24 hours.
What was the windiest day in Yamaguchi?
The windiest day measured in Yamaguchi between 1940 and 2025 was 7 September 2004, with winds reaching 63.6 km/h.
What is the warmest month in Yamaguchi?
The warmest month in Yamaguchi is August (26.7 °C on average); the coldest is January (4.2 °C).
How much does it rain in Yamaguchi?
Yamaguchi receives on average 1,650 mm of precipitation per year, spread over about 143 rainy days.
Is it sunny in Yamaguchi?
Yamaguchi gets on average 8.7 hours of sunshine per day, roughly 3,175 hours per year over 1940-2025.
What is the biggest single-day snowfall in Yamaguchi?
The heaviest 24-hour snowfall measured in Yamaguchi between 1940 and 2025 was 15 February 1968, with 25.5 cm.
Are there tropical nights in Yamaguchi?
Yes: Yamaguchi has on average 78 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Yamaguchi?
In Yamaguchi, between 1940 and 2025, the highest apparent temperature reached 44.2 °C on 26 July 2018, and the lowest was -14.6 °C on 16 February 1977.
Compare Yamaguchi with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Yamaguchi