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Tomakomai, Hokkaido Weather by Month and Climate Averages
Monthly normals · Rain · Snow
Sunshine · Freeze dates · Records · Best time to visit
What is the weather like in Tomakomai, Hokkaido?
Tomakomai, Hokkaido gets 1135 mm of precipitation a year over about 120 rainy days. August is the warmest month (average high 24°C) and January the coldest (average low -9°C).
Humid continental climate
Tomakomai, Hokkaido has warm summers and cold winters. Daytime highs range from about 0°C in January to 24°C in August. August is usually the wettest month. The most comfortable time to visit is typically June to July and September, when daytime highs sit near 20°C.
| Season | Months | Avg low | Avg high |
|---|---|---|---|
| Winter | Dec–Feb | -8° | 1° |
| Spring | Mar–May | 1° | 9° |
| Summer | Jun–Aug | 15° | 21° |
| Autumn | Sep–Nov | 6° | 16° |
How much rain does Tomakomai get?
Tomakomai gets 1135 mm of precipitation in an average year, spread over about 120 days with measurable rain. That is more rainy days than 57% of Japan.
August is the wettest month, with 177 mm. February is the driest, with 34 mm. August has the most rainy days, about 12.
The longest dry spell in the last five years lasted 14 days, to January 9, 2023.
From October 2025 to September 2026 Tomakomai got 2658 mm of rain, against a normal of 1135 mm for those months. September 2026 had the most, with 1292 mm.
Tomakomai weather by month
Tomakomai weather in January
In January, Tomakomai averages a high of 0°C and a low of -9°C. It gets 38 mm of precipitation over about 10 rainy days. Estimated sunshine is 40% of daylight hours, derived from ERA5 cloud cover. The January record high is 9°C (1995) and the record low is -19°C (2000).
Tomakomai weather in February
In February, Tomakomai averages a high of 1°C and a low of -9°C. It gets 34 mm of precipitation over about 10 rainy days. Estimated sunshine is 39% of daylight hours, derived from ERA5 cloud cover. The February record high is 13°C (2024) and the record low is -21°C (1977).
Tomakomai weather in March
In March, Tomakomai averages a high of 4°C and a low of -4°C. It gets 51 mm of precipitation over about 11 rainy days. Estimated sunshine is 44% of daylight hours, derived from ERA5 cloud cover. The March record high is 16°C (2021) and the record low is -15°C (2005).
Tomakomai weather in April
In April, Tomakomai averages a high of 10°C and a low of 1°C. It gets 69 mm of precipitation over about 10 rainy days. Estimated sunshine is 44% of daylight hours, derived from ERA5 cloud cover. The April record high is 22°C (2018) and the record low is -9°C (1978).
Tomakomai weather in May
In May, Tomakomai averages a high of 14°C and a low of 6°C. It gets 126 mm of precipitation over about 10 rainy days. Estimated sunshine is 38% of daylight hours, derived from ERA5 cloud cover. The May record high is 27°C (1999) and the record low is -2°C (2001).
Tomakomai weather in June
In June, Tomakomai averages a high of 18°C and a low of 11°C. It gets 105 mm of precipitation over about 9 rainy days. Estimated sunshine is 32% of daylight hours, derived from ERA5 cloud cover. The June record high is 31°C (2010) and the record low is 3°C (1972). June is one of the most comfortable months to visit.
Tomakomai weather in July
In July, Tomakomai averages a high of 22°C and a low of 16°C. It gets 150 mm of precipitation over about 11 rainy days. Estimated sunshine is 30% of daylight hours, derived from ERA5 cloud cover. The July record high is 34°C (2022) and the record low is 7°C (1976). July is one of the most comfortable months to visit.
Tomakomai weather in August
In August, Tomakomai averages a high of 24°C and a low of 18°C. It gets 177 mm of precipitation over about 12 rainy days. Estimated sunshine is 27% of daylight hours, derived from ERA5 cloud cover. The August record high is 36°C (2007) and the record low is 9°C (1971).
Tomakomai weather in September
In September, Tomakomai averages a high of 22°C and a low of 13°C. It gets 155 mm of precipitation over about 10 rainy days. Estimated sunshine is 32% of daylight hours, derived from ERA5 cloud cover. The September record high is 29°C (2019) and the record low is 3°C (2017). September is one of the most comfortable months to visit.
Tomakomai weather in October
In October, Tomakomai averages a high of 16°C and a low of 6°C. It gets 103 mm of precipitation over about 9 rainy days. Estimated sunshine is 43% of daylight hours, derived from ERA5 cloud cover. The October record high is 27°C (2021) and the record low is -4°C (1970).
Tomakomai weather in November
In November, Tomakomai averages a high of 9°C and a low of -1°C. It gets 74 mm of precipitation over about 9 rainy days. Estimated sunshine is 42% of daylight hours, derived from ERA5 cloud cover. The November record high is 21°C (2023) and the record low is -11°C (2016).
Tomakomai weather in December
In December, Tomakomai averages a high of 3°C and a low of -6°C. It gets 53 mm of precipitation over about 9 rainy days. Estimated sunshine is 44% of daylight hours, derived from ERA5 cloud cover. The December record high is 18°C (1998) and the record low is -16°C (1985).
Sunshine, humidity and wind in Tomakomai
March is the sunniest month in Tomakomai, with estimated sunshine of 44% of daylight hours from ERA5 cloud cover. August is the cloudiest, at 27%. The annual cloud-cover estimate is 38% of daylight hours; it is not a measurement of sunshine duration. Tomakomai is cloudier than 53% of Japan.
Humidity peaks in July at 88% and is lowest in April at 72%.
First and last freeze in Tomakomai
The first fall freeze in Tomakomai typically comes around October 28, and the last spring freeze around April 26. That leaves a frost-free growing season of about 185 days.
Tomakomai weather records
These records cover TOMAKOMAI during 1970–2026. Earlier records or other stations in the city may differ.
The hottest temperature on record at the Tomakomai station is 36°C, on August 15, 2007. The coldest is -21°C, on February 2, 1977.
The wettest day in the available station history brought 454 mm of precipitation, on September 3, 2026.
48 all-time records have been set at the station since 1970.
The best time to visit Tomakomai
The most comfortable time to visit is typically June to July and September, when daytime highs sit near 20°C.
Winter (December–February) is cold, with average highs around 1°C and lows near -8°C.
Spring (March–May) is chilly, with average highs around 10°C and lows near 1°C.
Summer (June–August) is warm, with average highs around 21°C and lows near 15°C. It can feel humid.
Autumn (September–November) is mild, with average highs around 16°C and lows near 6°C.
Monthly climate
| Month | Average low | Average high | Precip | Rain days | Humidity | Estimated sunshine | Record high | Record low |
|---|---|---|---|---|---|---|---|---|
| January | -9° | 0° | 38 mm | 10 | 74% | 40% | 9° | -19° |
| February | -9° | 1° | 34 mm | 10 | 74% | 39% | 13° | -21° |
| March | -4° | 4° | 51 mm | 11 | 75% | 44% | 16° | -15° |
| April | 1° | 10° | 69 mm | 10 | 72% | 44% | 22° | -9° |
| May | 6° | 14° | 126 mm | 10 | 79% | 38% | 27° | -2° |
| June | 11° | 18° | 105 mm | 9 | 85% | 32% | 31° | 3° |
| July | 16° | 22° | 150 mm | 11 | 88% | 30% | 34° | 7° |
| August | 18° | 24° | 177 mm | 12 | 87% | 27% | 36° | 9° |
| September | 13° | 22° | 155 mm | 10 | 81% | 32% | 29° | 3° |
| October | 6° | 16° | 103 mm | 9 | 77% | 43% | 27° | -4° |
| November | -1° | 9° | 74 mm | 9 | 74% | 42% | 21° | -11° |
| December | -6° | 3° | 53 mm | 9 | 72% | 44% | 18° | -16° |
Station: TOMAKOMAI, 5 km from the city. Temperature normal baseline: 1991–2020, calculated from available NOAA GHCN-Daily observations. Available station history: 1970–2026; record values refer to this station and period, not the entire city’s history. Precipitation includes rain and the water equivalent of frozen precipitation; snowfall depth is shown separately when available. Sources and methods
From ERA5 reanalysis. Sunshine is estimated from cloud cover.
Tomakomai climate questions
How much rain does Tomakomai get?
Tomakomai gets 1135 mm of precipitation in an average year, over about 120 rainy days.
What is the wettest month in Tomakomai?
August is the wettest month in Tomakomai, with 177 mm. February is the driest, with 34 mm.
How many rainy days does Tomakomai have a year?
Tomakomai has about 120 days with measurable rain in an average year. August has the most, about 12.
What is the hottest month in Tomakomai?
August is the warmest month in Tomakomai, with an average high of 24°C.
What is the coldest month in Tomakomai?
January is the coldest month in Tomakomai, with an average low of -9°C.
What is the record high temperature in Tomakomai?
Within the available 1970–2026 station history, the record high at the Tomakomai station is 36°C, set on August 15, 2007. The record low is -21°C, on February 2, 1977.
What is the sunniest month in Tomakomai?
March is the sunniest month in Tomakomai, with estimated sunshine of 44% of daylight hours from ERA5 cloud cover. August is the cloudiest.
When is the first frost in Tomakomai?
The first fall freeze in Tomakomai typically comes around October 28. The last spring freeze is around April 26.
What is the best time to visit Tomakomai?
The most comfortable time to visit is typically June to July and September, when daytime highs sit near 20°C.