Sōma climate — normals and trends
Sōma (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 13.3 °C and it receives 1,403 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 (24.0 °C on average) and the coldest is February (4.0 °C). Rainfall peaks in September.
Sōma averages 10 frost days, 0 hot days (≥ 30 °C) and 138 rainy days per year.
Sōma has warmed by +1.4 °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 17 to 3 per year over the period.
The hottest day of the period reached 32.5 °C (on 5 August 2025) and the coldest -4.5 °C (on 7 February 1984).
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
SōmaFukushima
- coords
- 37.79°, 140.93°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
13.3°C
Average daily high
15.0°C
Average daily low
11.7°C
Annual rainfall
1,403mm
Sunshine / day
8.4h
Mean relative humidity
75%
Average peak wind
23.6km/h
Seasonal range
20.0°C
Frost days (< 0 °C)
10 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
138 d/yr
Annual snowfall
26.0 cm
Average feels-like high
13.9 °C
Average feels-like low
9.3 °C
Average peak gust
35.6 km/h
Tropical nights (≥ 20 °C)
68 d/yr
Solar radiation
13.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.4 °C
since 1940
+0.2 °C per decade · r² = 0.32 · 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
32.5 °C
5 August 2025
Coldest day
-4.5 °C
7 February 1984
Wettest day
179 mm
31 August 1971
Windiest day
85.5 km/h
24 December 1980
Strongest gust
142.6 km/h
24 December 1980
Hottest feels-like
38.3 °C
5 August 2025
Coldest feels-like
-12.1 °C
2 February 1996
Snowiest day
18.6 cm
15 January 1998
Sunniest day
14.3 h
22 June 2018
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 | 7.7 °C | +1.6 °C | 51 mm | -4 mm |
| Feb | 6.5 °C | +0.4 °C | 26 mm | -35 mm |
| Mar | 10.1 °C | +1.8 °C | 98 mm | +5 mm |
| Apr | 13.3 °C | +0.8 °C | 109 mm | +4 mm |
| May | 16.9 °C | +0.7 °C | 252 mm | +133 mm |
| Jun | 22.2 °C | +3.1 °C | 113 mm | -36 mm |
| Jul | 26.5 °C | +3.7 °C | 62 mm | -110 mm |
| Aug | 28.0 °C | +2.9 °C | 158 mm | +16 mm |
| Sep | 25.6 °C | +2.7 °C | 165 mm | -37 mm |
| Oct | 19.3 °C | +0.9 °C | 197 mm | +30 mm |
| Nov | 14.4 °C | +0.7 °C | 32 mm | -46 mm |
| Dec | 10.4 °C | +1.4 °C | 73 mm | +13 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 Sōma?
Sōma has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 13.3 °C and it receives 1,403 mm of precipitation per year.
What is the hottest day ever recorded in Sōma?
The hottest day measured in Sōma between 1940 and 2025 was 5 August 2025, reaching 32.5 °C.
What is the coldest day in Sōma?
The coldest day measured in Sōma between 1940 and 2025 was 7 February 1984, at -4.5 °C.
Does it snow in Sōma?
Yes. Sōma gets on average 26.0 cm of snow per year and has around 10 frost days.
Has the climate of Sōma warmed?
Yes: Sōma warmed by +1.4 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Sōma?
The wettest day measured in Sōma between 1940 and 2025 was 31 August 1971, with 179 mm of rain in 24 hours.
What was the windiest day in Sōma?
The windiest day measured in Sōma between 1940 and 2025 was 24 December 1980, with winds reaching 85.5 km/h.
What is the warmest month in Sōma?
The warmest month in Sōma is August (24.0 °C on average); the coldest is February (4.0 °C).
How much does it rain in Sōma?
Sōma receives on average 1,403 mm of precipitation per year, spread over about 138 rainy days.
Is it sunny in Sōma?
Sōma gets on average 8.4 hours of sunshine per day, roughly 3,066 hours per year over 1940-2025.
What is the biggest single-day snowfall in Sōma?
The heaviest 24-hour snowfall measured in Sōma between 1940 and 2025 was 15 January 1998, with 18.6 cm.
Are there tropical nights in Sōma?
Yes: Sōma has on average 68 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Sōma?
In Sōma, between 1940 and 2025, the highest apparent temperature reached 38.3 °C on 5 August 2025, and the lowest was -12.1 °C on 2 February 1996.
Compare Sōma with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Sōma