Isesaki, Gunma Weather by Month and Climate Averages

How much rain does Isesaki get?

Isesaki gets 1169 mm of precipitation in an average year, spread over about 99 days with measurable rain. That is fewer rainy days than 77% of Japan.

September is the wettest month, with 193 mm. December is the driest, with 22 mm. July has the most rainy days, about 15.

The longest dry spell in the last five years lasted 41 days, to February 6, 2026.

Isesaki weather by month

Isesaki weather in January

In January, Isesaki averages a high of 9°C and a low of -1°C. It gets 26 mm of precipitation over about 3 rainy days. The sun is out about 60% of daylight hours. The January record high is 19°C (1996) and the record low is -8°C (1970).

Isesaki weather in February

In February, Isesaki averages a high of 10°C and a low of -1°C. It gets 24 mm of precipitation over about 4 rainy days. The sun is out about 57% of daylight hours. The February record high is 23°C (1987) and the record low is -9°C (1981).

Isesaki weather in March

In March, Isesaki averages a high of 14°C and a low of 3°C. It gets 53 mm of precipitation over about 7 rainy days. The sun is out about 46% of daylight hours. The March record high is 27°C (1998) and the record low is -7°C (1977).

Isesaki weather in April

In April, Isesaki averages a high of 19°C and a low of 8°C. It gets 71 mm of precipitation over about 8 rainy days. The sun is out about 43% of daylight hours. The April record high is 32°C (1983) and the record low is -2°C (1978). April is one of the most comfortable months to visit.

Isesaki weather in May

In May, Isesaki averages a high of 24°C and a low of 13°C. It gets 94 mm of precipitation over about 9 rainy days. The sun is out about 33% of daylight hours. The May record high is 37°C (1993) and the record low is 3°C (1991). May is one of the most comfortable months to visit.

Isesaki weather in June

In June, Isesaki averages a high of 27°C and a low of 18°C. It gets 144 mm of precipitation over about 13 rainy days. The sun is out about 24% of daylight hours. The June record high is 39°C (2022) and the record low is 8°C (1978).

Isesaki weather in July

In July, Isesaki averages a high of 31°C and a low of 22°C. It gets 179 mm of precipitation over about 15 rainy days. The sun is out about 24% of daylight hours. The July record high is 40°C (2001) and the record low is 12°C (1976).

Isesaki weather in August

In August, Isesaki averages a high of 32°C and a low of 23°C. It gets 186 mm of precipitation over about 12 rainy days. The sun is out about 32% of daylight hours. The August record high is 41°C (2025) and the record low is 15°C (1976).

Isesaki weather in September

In September, Isesaki averages a high of 27°C and a low of 19°C. It gets 193 mm of precipitation over about 12 rainy days. The sun is out about 26% of daylight hours. The September record high is 38°C (1984) and the record low is 8°C (1995).

Isesaki weather in October

In October, Isesaki averages a high of 22°C and a low of 13°C. It gets 137 mm of precipitation over about 8 rainy days. The sun is out about 42% of daylight hours. The October record high is 32°C (2012) and the record low is 3°C (1971). October is one of the most comfortable months to visit.

Isesaki weather in November

In November, Isesaki averages a high of 17°C and a low of 7°C. It gets 40 mm of precipitation over about 5 rainy days. The sun is out about 61% of daylight hours. The November record high is 26°C (2019) and the record low is -2°C (1974).

Isesaki weather in December

In December, Isesaki averages a high of 12°C and a low of 2°C. It gets 22 mm of precipitation over about 3 rainy days. The sun is out about 65% of daylight hours. The December record high is 25°C (1990) and the record low is -6°C (1976).

Sunshine, humidity and wind in Isesaki

December is the sunniest month in Isesaki, with sunshine about 65% of daylight hours. June is the cloudiest, at 24%. Over the year the sun shines about 43% of daylight hours. Isesaki is sunnier than 90% of Japan.

Humidity peaks in September at 79% and is lowest in February at 55%.

Isesaki has about 29 days a year above 32°C. Isesaki is hotter than 76% of Japan.

First and last freeze in Isesaki

The first fall freeze in Isesaki typically comes around December 9, and the last spring freeze around March 23. That leaves a frost-free growing season of about 261 days.

Isesaki weather records

The hottest temperature on record at the Isesaki station is 41°C, on August 5, 2025. The coldest is -9°C, on February 27, 1981.

The wettest day on record brought 340 mm of rain, on August 23, 1993.

45 all-time records have been set at the station since 1970.

The best time to visit Isesaki

The most comfortable time to visit is typically April to May and October, when daytime highs sit near 22°C.

Winter (December–February) is chilly, with average highs around 10°C and lows near 0°C.

Spring (March–May) is mild, with average highs around 19°C and lows near 8°C.

Summer (June–August) is hot, with average highs around 30°C and lows near 21°C. It can feel humid.

Autumn (September–November) is warm, with average highs around 22°C and lows near 13°C.

Isesaki climate questions

How much rain does Isesaki get?

Isesaki gets 1169 mm of precipitation in an average year, over about 99 rainy days.

What is the wettest month in Isesaki?

September is the wettest month in Isesaki, with 193 mm. December is the driest, with 22 mm.

How many rainy days does Isesaki have a year?

Isesaki has about 99 days with measurable rain in an average year. July has the most, about 15.

What is the hottest month in Isesaki?

August is the warmest month in Isesaki, with an average high of 32°C.

What is the coldest month in Isesaki?

January is the coldest month in Isesaki, with an average low of -1°C.

What is the record high temperature in Isesaki?

The record high at the Isesaki station is 41°C, set on August 5, 2025. The record low is -9°C, on February 27, 1981.

What is the sunniest month in Isesaki?

December is the sunniest month in Isesaki, with sunshine about 65% of daylight hours. June is the cloudiest.

When is the first frost in Isesaki?

The first fall freeze in Isesaki typically comes around December 9. The last spring freeze is around March 23.

What is the best time to visit Isesaki?

The most comfortable time to visit is typically April to May and October, when daytime highs sit near 22°C.