Shūnan, Yamaguchi Weather by Month and Climate Averages

How much rain does Shūnan get?

Shūnan gets 1734 mm of precipitation in an average year, spread over about 109 days with measurable rain. That is fewer rainy days than 54% of Japan.

July is the wettest month, with 289 mm. December is the driest, with 66 mm. June has the most rainy days, about 11.

The longest dry spell in the last five years lasted 27 days, to November 5, 2023.

Shūnan weather by month

Shūnan weather in January

In January, Shūnan averages a high of 9°C and a low of 0°C. It gets 68 mm of precipitation over about 10 rainy days. The sun is out about 42% of daylight hours. The January record high is 18°C (1997) and the record low is -8°C (2004).

Shūnan weather in February

In February, Shūnan averages a high of 11°C and a low of 0°C. It gets 75 mm of precipitation over about 10 rainy days. The sun is out about 42% of daylight hours. The February record high is 22°C (1993) and the record low is -9°C (1977).

Shūnan weather in March

In March, Shūnan averages a high of 14°C and a low of 3°C. It gets 127 mm of precipitation over about 10 rainy days. The sun is out about 41% of daylight hours. The March record high is 27°C (2025) and the record low is -8°C (1977).

Shūnan weather in April

In April, Shūnan averages a high of 20°C and a low of 8°C. It gets 155 mm of precipitation over about 9 rainy days. The sun is out about 42% of daylight hours. The April record high is 29°C (2004) and the record low is -1°C (1985). April is one of the most comfortable months to visit.

Shūnan weather in May

In May, Shūnan averages a high of 25°C and a low of 13°C. It gets 184 mm of precipitation over about 8 rainy days. The sun is out about 36% of daylight hours. The May record high is 34°C (2019) and the record low is 3°C (1971). May is one of the most comfortable months to visit.

Shūnan weather in June

In June, Shūnan averages a high of 28°C and a low of 18°C. It gets 267 mm of precipitation over about 11 rainy days. The sun is out about 25% of daylight hours. The June record high is 36°C (2025) and the record low is 8°C (1978).

Shūnan weather in July

In July, Shūnan averages a high of 31°C and a low of 23°C. It gets 289 mm of precipitation over about 11 rainy days. The sun is out about 27% of daylight hours. The July record high is 39°C (2018) and the record low is 15°C (1982).

Shūnan weather in August

In August, Shūnan averages a high of 33°C and a low of 23°C. It gets 190 mm of precipitation over about 9 rainy days. The sun is out about 40% of daylight hours. The August record high is 39°C (2026) and the record low is 16°C (1971).

Shūnan weather in September

In September, Shūnan averages a high of 29°C and a low of 19°C. It gets 150 mm of precipitation over about 9 rainy days. The sun is out about 39% of daylight hours. The September record high is 37°C (2025) and the record low is 7°C (1987).

Shūnan weather in October

In October, Shūnan averages a high of 23°C and a low of 13°C. It gets 86 mm of precipitation over about 6 rainy days. The sun is out about 53% of daylight hours. The October record high is 32°C (2021) and the record low is 1°C (1986). October is one of the most comfortable months to visit.

Shūnan weather in November

In November, Shūnan averages a high of 18°C and a low of 7°C. It gets 76 mm of precipitation over about 8 rainy days. The sun is out about 54% of daylight hours. The November record high is 28°C (2023) and the record low is -2°C (1976). November is one of the most comfortable months to visit.

Shūnan weather in December

In December, Shūnan averages a high of 12°C and a low of 2°C. It gets 66 mm of precipitation over about 10 rainy days. The sun is out about 44% of daylight hours. The December record high is 23°C (2018) and the record low is -6°C (1980).

Sunshine, humidity and wind in Shūnan

November is the sunniest month in Shūnan, with sunshine about 54% of daylight hours. June is the cloudiest, at 25%. Over the year the sun shines about 40% of daylight hours. Shūnan is sunnier than 65% of Japan.

Humidity peaks in July at 85% and is lowest in December at 66%.

Shūnan has about 31 days a year above 32°C. Shūnan is hotter than 81% of Japan.

First and last freeze in Shūnan

The first fall freeze in Shūnan typically comes around December 6, and the last spring freeze around March 25. That leaves a frost-free growing season of about 256 days.

Shūnan weather records

The hottest temperature on record at the Shūnan station is 39°C, on August 3, 2026. The coldest is -9°C, on February 18, 1977.

The wettest day on record brought 297 mm of rain, on July 11, 1972.

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

The best time to visit Shūnan

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

Winter (December–February) is chilly, with average highs around 11°C and lows near 1°C.

Spring (March–May) is mild, with average highs around 20°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 23°C and lows near 13°C.

Shūnan climate questions

How much rain does Shūnan get?

Shūnan gets 1734 mm of precipitation in an average year, over about 109 rainy days.

What is the wettest month in Shūnan?

July is the wettest month in Shūnan, with 289 mm. December is the driest, with 66 mm.

How many rainy days does Shūnan have a year?

Shūnan has about 109 days with measurable rain in an average year. June has the most, about 11.

What is the hottest month in Shūnan?

August is the warmest month in Shūnan, with an average high of 33°C.

What is the coldest month in Shūnan?

January is the coldest month in Shūnan, with an average low of 0°C.

What is the record high temperature in Shūnan?

The record high at the Shūnan station is 39°C, set on August 3, 2026. The record low is -9°C, on February 18, 1977.

What is the sunniest month in Shūnan?

November is the sunniest month in Shūnan, with sunshine about 54% of daylight hours. June is the cloudiest.

When is the first frost in Shūnan?

The first fall freeze in Shūnan typically comes around December 6. The last spring freeze is around March 25.

What is the best time to visit Shūnan?

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