Iwakuni, Yamaguchi Weather by Month and Climate Averages

How much rain does Iwakuni get?

Iwakuni gets 1448 mm of precipitation in an average year, spread over about 98 days with measurable rain. That is fewer rainy days than 82% of Japan.

July is the wettest month, with 258 mm. January is the driest, with 40 mm. July has the most rainy days, about 11.

The longest dry spell in the last five years lasted 25 days, to February 7, 2026.

Iwakuni weather by month

Iwakuni weather in January

In January, Iwakuni averages a high of 10°C and a low of 1°C. It gets 40 mm of precipitation over about 7 rainy days. The sun is out about 46% of daylight hours. The January record high is 18°C (1997) and the record low is -5°C (1977).

Iwakuni weather in February

In February, Iwakuni averages a high of 11°C and a low of 2°C. It gets 58 mm of precipitation over about 7 rainy days. The sun is out about 44% of daylight hours. The February record high is 22°C (2009) and the record low is -8°C (1977).

Iwakuni weather in March

In March, Iwakuni averages a high of 14°C and a low of 4°C. It gets 107 mm of precipitation over about 9 rainy days. The sun is out about 41% of daylight hours. The March record high is 24°C (2025) and the record low is -6°C (1977).

Iwakuni weather in April

In April, Iwakuni averages a high of 20°C and a low of 9°C. It gets 133 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 (1987). April is one of the most comfortable months to visit.

Iwakuni weather in May

In May, Iwakuni averages a high of 24°C and a low of 14°C. It gets 155 mm of precipitation over about 8 rainy days. The sun is out about 36% of daylight hours. The May record high is 32°C (1998) and the record low is 4°C (1980). May is one of the most comfortable months to visit.

Iwakuni weather in June

In June, Iwakuni averages a high of 27°C and a low of 19°C. It gets 214 mm of precipitation over about 11 rainy days. The sun is out about 24% of daylight hours. The June record high is 33°C (2004) and the record low is 10°C (1978).

Iwakuni weather in July

In July, Iwakuni averages a high of 31°C and a low of 24°C. It gets 258 mm of precipitation over about 11 rainy days. The sun is out about 27% of daylight hours. The July record high is 39°C (1994) and the record low is 17°C (1982).

Iwakuni weather in August

In August, Iwakuni averages a high of 33°C and a low of 25°C. It gets 114 mm of precipitation over about 8 rainy days. The sun is out about 39% of daylight hours. The August record high is 38°C (2026) and the record low is 17°C (1972).

Iwakuni weather in September

In September, Iwakuni averages a high of 29°C and a low of 21°C. It gets 152 mm of precipitation over about 9 rainy days. The sun is out about 37% of daylight hours. The September record high is 37°C (2010) and the record low is 9°C (1972).

Iwakuni weather in October

In October, Iwakuni averages a high of 24°C and a low of 14°C. It gets 102 mm of precipitation over about 6 rainy days. The sun is out about 51% of daylight hours. The October record high is 32°C (2019) and the record low is 3°C (1986). October is one of the most comfortable months to visit.

Iwakuni weather in November

In November, Iwakuni averages a high of 18°C and a low of 8°C. It gets 62 mm of precipitation over about 6 rainy days. The sun is out about 55% of daylight hours. The November record high is 25°C (2011) and the record low is -1°C (1970). November is one of the most comfortable months to visit.

Iwakuni weather in December

In December, Iwakuni averages a high of 12°C and a low of 3°C. It gets 52 mm of precipitation over about 7 rainy days. The sun is out about 52% of daylight hours. The December record high is 21°C (2018) and the record low is -4°C (1980).

Sunshine, humidity and wind in Iwakuni

November is the sunniest month in Iwakuni, with sunshine about 55% of daylight hours. June is the cloudiest, at 24%. Over the year the sun shines about 41% of daylight hours. Iwakuni is sunnier than 72% of Japan.

Humidity peaks in July at 81% and is lowest in April at 66%.

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

First and last freeze in Iwakuni

The first fall freeze in Iwakuni typically comes around December 18, and the last spring freeze around March 5. That leaves a frost-free growing season of about 288 days.

Iwakuni weather records

The hottest temperature on record at the Iwakuni station is 39°C, on July 17, 1994. The coldest is -8°C, on February 17, 1977.

The wettest day on record brought 293 mm of rain, on July 7, 2018.

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

The best time to visit Iwakuni

The most comfortable time to visit is typically April to May and October to November, when daytime highs sit near 21°C.

Winter (December–February) is chilly, with average highs around 11°C and lows near 2°C.

Spring (March–May) is mild, with average highs around 20°C and lows near 9°C.

Summer (June–August) is hot, with average highs around 30°C and lows near 23°C. It can feel humid.

Autumn (September–November) is warm, with average highs around 24°C and lows near 14°C.

Iwakuni climate questions

How much rain does Iwakuni get?

Iwakuni gets 1448 mm of precipitation in an average year, over about 98 rainy days.

What is the wettest month in Iwakuni?

July is the wettest month in Iwakuni, with 258 mm. January is the driest, with 40 mm.

How many rainy days does Iwakuni have a year?

Iwakuni has about 98 days with measurable rain in an average year. July has the most, about 11.

What is the hottest month in Iwakuni?

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

What is the coldest month in Iwakuni?

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

What is the record high temperature in Iwakuni?

The record high at the Iwakuni station is 39°C, set on July 17, 1994. The record low is -8°C, on February 17, 1977.

What is the sunniest month in Iwakuni?

November is the sunniest month in Iwakuni, with sunshine about 55% of daylight hours. June is the cloudiest.

When is the first frost in Iwakuni?

The first fall freeze in Iwakuni typically comes around December 18. The last spring freeze is around March 5.

What is the best time to visit Iwakuni?

The most comfortable time to visit is typically April to May and October to November, when daytime highs sit near 21°C.