Unnan climate — normals and trends
Unnan (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 13.6 °C and it receives 1,731 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 (25.7 °C on average) and the coldest is January (2.1 °C). Rainfall peaks in July.
Unnan averages 59 frost days, 30 hot days (≥ 30 °C) and 177 rainy days per year.
Unnan has warmed by +2.6 °C between 1940 and 2025, or +0.31 °C per decade. This trend is statistically significant.
The number of frost days there went from about 83 to 35 per year over the period.
The hottest day of the period reached 37.4 °C (on 9 August 1994) and the coldest -14.6 °C (on 9 January 1944).
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
UnnanShimane
- coords
- 35.24°, 132.90°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
13.6°C
Average daily high
17.7°C
Average daily low
9.7°C
Annual rainfall
1,731mm
Sunshine / day
8.7h
Mean relative humidity
76%
Average peak wind
16.7km/h
Seasonal range
23.6°C
Frost days (< 0 °C)
59 d/yr
Hot days (≥ 30 °C)
30 d/yr
Rainy days (≥ 1 mm)
177 d/yr
Annual snowfall
100.1 cm
Average feels-like high
17.0 °C
Average feels-like low
8.3 °C
Average peak gust
40.6 km/h
Tropical nights (≥ 20 °C)
65 d/yr
Solar radiation
14.6 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.6 °C
since 1940
+0.3 °C per decade · r² = 0.69 · 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
37.4 °C
9 August 1994
Coldest day
-14.6 °C
9 January 1944
Wettest day
181 mm
11 July 1972
Windiest day
61.9 km/h
7 September 2004
Strongest gust
172.8 km/h
27 September 1991
Hottest feels-like
42.0 °C
1 August 2023
Coldest feels-like
-19.4 °C
9 January 1944
Snowiest day
36.3 cm
16 March 1965
Sunniest day
14.0 h
27 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 | 6.2 °C | +0.7 °C | 86 mm | -19 mm |
| Feb | 4.5 °C | -1.9 °C | 110 mm | +8 mm |
| Mar | 11.9 °C | +1.2 °C | 182 mm | +63 mm |
| Apr | 17.9 °C | +0.9 °C | 75 mm | -46 mm |
| May | 21.7 °C | +0.3 °C | 175 mm | +40 mm |
| Jun | 27.4 °C | +2.7 °C | 183 mm | -13 mm |
| Jul | 32.3 °C | +3.9 °C | 64 mm | -177 mm |
| Aug | 31.3 °C | +1.6 °C | 282 mm | +106 mm |
| Sep | 27.6 °C | +2.3 °C | 164 mm | -54 mm |
| Oct | 21.2 °C | +1.5 °C | 165 mm | +46 mm |
| Nov | 15.1 °C | +0.7 °C | 53 mm | -43 mm |
| Dec | 9.7 °C | +1.1 °C | 110 mm | +9 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 Unnan?
Unnan has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 13.6 °C and it receives 1,731 mm of precipitation per year.
What is the hottest day ever recorded in Unnan?
The hottest day measured in Unnan between 1940 and 2025 was 9 August 1994, reaching 37.4 °C.
What is the coldest day in Unnan?
The coldest day measured in Unnan between 1940 and 2025 was 9 January 1944, at -14.6 °C.
Does it snow in Unnan?
Yes. Unnan gets on average 100.1 cm of snow per year and has around 59 frost days.
Has the climate of Unnan warmed?
Yes: Unnan warmed by +2.6 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Unnan?
The wettest day measured in Unnan between 1940 and 2025 was 11 July 1972, with 181 mm of rain in 24 hours.
What was the windiest day in Unnan?
The windiest day measured in Unnan between 1940 and 2025 was 7 September 2004, with winds reaching 61.9 km/h.
What is the warmest month in Unnan?
The warmest month in Unnan is August (25.7 °C on average); the coldest is January (2.1 °C).
How much does it rain in Unnan?
Unnan receives on average 1,731 mm of precipitation per year, spread over about 177 rainy days.
Is it sunny in Unnan?
Unnan 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 Unnan?
The heaviest 24-hour snowfall measured in Unnan between 1940 and 2025 was 16 March 1965, with 36.3 cm.
Are there tropical nights in Unnan?
Yes: Unnan has on average 65 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Unnan?
In Unnan, between 1940 and 2025, the highest apparent temperature reached 42.0 °C on 1 August 2023, and the lowest was -19.4 °C on 9 January 1944.
Compare Unnan with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Unnan