Climate averages 1991–2020
Tomakomai weather
in December.
A cold month with moderate precipitation: the 10th warmest and the joint 3rd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a cold month in Tomakomai: daytime highs average 0.7°C and nights cool to about -4.2°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 63 mm of precipitation on roughly 9 days, which makes December a month with moderate precipitation (the joint 3rd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 9 h 07 min on an average December day.
The nearest other city in this atlas is Chitose (21 km away). In December its highs average 0.5°C, about as warm as Tomakomai, with 54 mm of precipitation.
Among the 303 cities listed in Japan, Tomakomai ranks 293rd of 303 for the warmest December highs and joint 109th of 303 for the driest December (precipitation, lowest first). The mean December high of those 303 cities is 9.5°C; Tomakomai is 8.8°C cooler than that mean.
From December to January, average highs fall by 2.7°C to -2.0°C, and monthly precipitation falls from 63 mm to 44 mm.
The annual picture
December in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Tomakomai climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -2.0°C-7.5°C | -7.5°C | 44 | 7.1 | 9.49 h |
| February | -1.3°C-7.4°C | -7.4°C | 44 | 7.4 | 10.511 h |
| March | 2.2°C-4.0°C | -4.0°C | 63 | 10.3 | 11.912 h |
| April | 7.5°C1.0°C | 1.0°C | 78 | 11.5 | 13.413 h |
| May | 12.7°C6.7°C | 6.7°C | 109 | 11.8 | 14.615 h |
| June | 16.7°C11.6°C | 11.6°C | 100 | 11.3 | 15.315 h |
| July | 20.6°C16.1°C | 16.1°C | 138 | 13.7 | 15.015 h |
| August | 22.5°C18.2°C | 18.2°C | 197 | 14.5 | 13.914 h |
| September | 20.1°C15.1°C | 15.1°C | 177 | 15.0 | 12.513 h |
| October | 14.3°C8.8°C | 8.8°C | 110 | 11.8 | 11.111 h |
| November | 7.3°C2.0°C | 2.0°C | 78 | 10.8 | 9.810 h |
| December, selected | 0.7°C-4.2°C | -4.2°C | 63 | 8.7 | 9.19 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Chitose in DecemberJapan · 21 kmHigh 0.5°C · Low -5.6°C · 54 mm precipitation
- Eniwa in DecemberJapan · 29 kmHigh -0.3°C · Low -6.5°C · 62 mm precipitation
- Sapporo in DecemberJapan · 52 kmHigh -0.3°C · Low -5.3°C · 73 mm precipitation
- Ebetsu in DecemberJapan · 53 kmHigh -0.9°C · Low -7.1°C · 62 mm precipitation
- Muroran in DecemberJapan · 62 kmHigh 0.3°C · Low -4.2°C · 69 mm precipitation
- Iwamizawa in DecemberJapan · 64 kmHigh -0.8°C · Low -8.0°C · 69 mm precipitation
- Otaru in DecemberJapan · 79 kmHigh 0.3°C · Low -2.7°C · 125 mm precipitation
- Hakodate in DecemberJapan · 119 kmHigh 2.1°C · Low -2.2°C · 70 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Tomakomai) is explained once on the Tomakomai year overview and on the Sources, method and limits page.