Shūnan climate — normals and trends
Shūnan (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 15.6 °C and it receives 1,672 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 (5.6 °C). Rainfall peaks in June.
Shūnan averages 4 frost days, 9 hot days (≥ 30 °C) and 135 rainy days per year.
Shūnan has warmed by +1.9 °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 7 to 1 per year over the period.
The hottest day of the period reached 33.6 °C (on 16 August 2024) and the coldest -5.5 °C (on 16 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
ShūnanYamaguchi
- coords
- 34.08°, 131.83°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
15.6°C
Average daily high
18.1°C
Average daily low
13.3°C
Annual rainfall
1,672mm
Sunshine / day
8.7h
Mean relative humidity
75%
Average peak wind
20.0km/h
Seasonal range
20.8°C
Frost days (< 0 °C)
4 d/yr
Hot days (≥ 30 °C)
9 d/yr
Rainy days (≥ 1 mm)
135 d/yr
Annual snowfall
8.7 cm
Average feels-like high
17.7 °C
Average feels-like low
11.8 °C
Average peak gust
37.1 km/h
Tropical nights (≥ 20 °C)
93 d/yr
Solar radiation
14.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.9 °C
since 1940
+0.2 °C per decade · r² = 0.63 · 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
33.6 °C
16 August 2024
Coldest day
-5.5 °C
16 February 1977
Wettest day
205 mm
6 September 2005
Windiest day
86.3 km/h
27 September 1991
Strongest gust
192.6 km/h
7 September 2004
Hottest feels-like
40.8 °C
4 August 2024
Coldest feels-like
-13.8 °C
26 February 1981
Snowiest day
15.6 cm
15 February 1968
Sunniest day
13.9 h
14 June 2024
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 | +0.6 °C | 35 mm | -27 mm |
| Feb | 6.9 °C | -1.7 °C | 63 mm | -16 mm |
| Mar | 12.5 °C | +0.8 °C | 158 mm | +40 mm |
| Apr | 16.6 °C | +0.4 °C | 103 mm | -53 mm |
| May | 19.9 °C | -0.1 °C | 279 mm | +105 mm |
| Jun | 24.6 °C | +1.4 °C | 332 mm | +68 mm |
| Jul | 29.7 °C | +2.7 °C | 86 mm | -155 mm |
| Aug | 30.2 °C | +1.6 °C | 232 mm | +80 mm |
| Sep | 28.1 °C | +2.3 °C | 293 mm | +109 mm |
| Oct | 23.3 °C | +2.1 °C | 90 mm | -15 mm |
| Nov | 17.0 °C | +1.0 °C | 36 mm | -42 mm |
| Dec | 12.1 °C | +1.5 °C | 55 mm | -5 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 Shūnan?
Shūnan has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 15.6 °C and it receives 1,672 mm of precipitation per year.
What is the hottest day ever recorded in Shūnan?
The hottest day measured in Shūnan between 1940 and 2025 was 16 August 2024, reaching 33.6 °C.
What is the coldest day in Shūnan?
The coldest day measured in Shūnan between 1940 and 2025 was 16 February 1977, at -5.5 °C.
Does it snow in Shūnan?
Yes. Shūnan gets on average 8.7 cm of snow per year and has around 4 frost days.
Has the climate of Shūnan warmed?
Yes: Shūnan warmed by +1.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Shūnan?
The wettest day measured in Shūnan between 1940 and 2025 was 6 September 2005, with 205 mm of rain in 24 hours.
What was the windiest day in Shūnan?
The windiest day measured in Shūnan between 1940 and 2025 was 27 September 1991, with winds reaching 86.3 km/h.
What is the warmest month in Shūnan?
The warmest month in Shūnan is August (26.4 °C on average); the coldest is January (5.6 °C).
How much does it rain in Shūnan?
Shūnan receives on average 1,672 mm of precipitation per year, spread over about 135 rainy days.
Is it sunny in Shūnan?
Shūnan 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 Shūnan?
The heaviest 24-hour snowfall measured in Shūnan between 1940 and 2025 was 15 February 1968, with 15.6 cm.
Are there tropical nights in Shūnan?
Yes: Shūnan has on average 93 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Shūnan?
In Shūnan, between 1940 and 2025, the highest apparent temperature reached 40.8 °C on 4 August 2024, and the lowest was -13.8 °C on 26 February 1981.
Compare Shūnan with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Shūnan