Tomakomai climate — normals and trends
Tomakomai (Japan) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 6.8 °C and it receives 1,209 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 (20.1 °C on average) and the coldest is January (-5.5 °C). Rainfall peaks in August.
Tomakomai averages 138 frost days, 0 hot days (≥ 30 °C) and 142 rainy days per year.
Tomakomai has warmed by +2.5 °C between 1940 and 2025, or +0.29 °C per decade. This trend is statistically significant.
The number of frost days there went from about 156 to 120 per year over the period.
The hottest day of the period reached 29.8 °C (on 23 July 2025) and the coldest -18.4 °C (on 20 January 1966).
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
TomakomaiHokkaido
- coords
- 42.64°, 141.60°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
6.8°C
Average daily high
9.5°C
Average daily low
4.1°C
Annual rainfall
1,209mm
Sunshine / day
8.8h
Mean relative humidity
79%
Average peak wind
17.5km/h
Seasonal range
25.6°C
Frost days (< 0 °C)
138 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
142 d/yr
Annual snowfall
140.0 cm
Average feels-like high
7.3 °C
Average feels-like low
1.4 °C
Average peak gust
35.2 km/h
Tropical nights (≥ 20 °C)
9 d/yr
Solar radiation
13.5 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.5 °C
since 1940
+0.3 °C per decade · r² = 0.64 · 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
29.8 °C
23 July 2025
Coldest day
-18.4 °C
20 January 1966
Wettest day
168 mm
17 August 2016
Windiest day
63.0 km/h
26 September 1954
Strongest gust
141.8 km/h
5 September 2018
Hottest feels-like
35.5 °C
25 July 2025
Coldest feels-like
-23.1 °C
20 January 1966
Snowiest day
40.2 cm
5 February 1969
Sunniest day
15.0 h
10 June 1941
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 | 0.2 °C | +3.0 °C | 38 mm | -9 mm |
| Feb | 0.9 °C | +2.9 °C | 41 mm | -4 mm |
| Mar | 3.4 °C | +1.8 °C | 82 mm | +16 mm |
| Apr | 9.2 °C | +2.1 °C | 123 mm | +35 mm |
| May | 14.7 °C | +2.5 °C | 75 mm | -30 mm |
| Jun | 20.3 °C | +4.2 °C | 115 mm | +9 mm |
| Jul | 24.9 °C | +4.8 °C | 92 mm | -39 mm |
| Aug | 25.4 °C | +3.1 °C | 180 mm | -3 mm |
| Sep | 22.3 °C | +2.8 °C | 279 mm | +99 mm |
| Oct | 13.7 °C | +0.3 °C | 95 mm | -25 mm |
| Nov | 7.8 °C | +1.8 °C | 123 mm | +41 mm |
| Dec | 1.8 °C | +1.8 °C | 97 mm | +40 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 Tomakomai?
Tomakomai has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 6.8 °C and it receives 1,209 mm of precipitation per year.
What is the hottest day ever recorded in Tomakomai?
The hottest day measured in Tomakomai between 1940 and 2025 was 23 July 2025, reaching 29.8 °C.
What is the coldest day in Tomakomai?
The coldest day measured in Tomakomai between 1940 and 2025 was 20 January 1966, at -18.4 °C.
Does it snow in Tomakomai?
Yes. Tomakomai gets on average 140.0 cm of snow per year and has around 138 frost days.
Has the climate of Tomakomai warmed?
Yes: Tomakomai warmed by +2.5 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Tomakomai?
The wettest day measured in Tomakomai between 1940 and 2025 was 17 August 2016, with 168 mm of rain in 24 hours.
What was the windiest day in Tomakomai?
The windiest day measured in Tomakomai between 1940 and 2025 was 26 September 1954, with winds reaching 63.0 km/h.
What is the warmest month in Tomakomai?
The warmest month in Tomakomai is August (20.1 °C on average); the coldest is January (-5.5 °C).
How much does it rain in Tomakomai?
Tomakomai receives on average 1,209 mm of precipitation per year, spread over about 142 rainy days.
Is it sunny in Tomakomai?
Tomakomai gets on average 8.8 hours of sunshine per day, roughly 3,212 hours per year over 1940-2025.
What is the biggest single-day snowfall in Tomakomai?
The heaviest 24-hour snowfall measured in Tomakomai between 1940 and 2025 was 5 February 1969, with 40.2 cm.
Are there tropical nights in Tomakomai?
Yes: Tomakomai has on average 9 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Tomakomai?
In Tomakomai, between 1940 and 2025, the highest apparent temperature reached 35.5 °C on 25 July 2025, and the lowest was -23.1 °C on 20 January 1966.
Compare Tomakomai with another city
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Nearby cities
The climate around Tomakomai