Hiroshima climate
Hiroshima (Japan) has a humid subtropical climate (Köppen Cfa). The average temperature over the year is 15 °C60 °F, and about 1,556 mm61 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Hiroshima climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin |
|---|---|---|---|---|
| Jan | 846 | 032 | 439 | 632.5 |
| Feb | 1049 | 133 | 541 | 752.9 |
| Mar | 1456 | 337 | 847 | 1094.3 |
| Apr | 1966 | 846 | 1356 | 1254.9 |
| May | 2475 | 1356 | 1965 | 1465.8 |
| Jun | 2781 | 1865 | 2373 | 2118.3 |
| Jul | 3087 | 2373 | 2780 | 26010 |
| Aug | 3289 | 2374 | 2781 | 1224.8 |
| Sep | 2882 | 1967 | 2474 | 1706.7 |
| Oct | 2272 | 1355 | 1864 | 1134.4 |
| Nov | 1661 | 745 | 1253 | 793.1 |
| Dec | 1050 | 236 | 643 | 843.3 |
| Year | 3289 | 032 | 1560 | 1,55661 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 84% | 75% | 2.2 | 10:05 |
| Feb | 83% | 74% | 2.8 | 10:54 |
| Mar | 80% | 68% | 3.9 | 11:53 |
| Apr | 78% | 66% | 4.8 | 13:00 |
| May | 79% | 66% | 5.4 | 13:57 |
| Jun | 82% | 79% | 4.8 | 14:26 |
| Jul | 86% | 74% | 4.8 | 14:14 |
| Aug | 83% | 66% | 5.1 | 13:26 |
| Sep | 83% | 70% | 4.1 | 12:20 |
| Oct | 82% | 63% | 3.4 | 11:15 |
| Nov | 84% | 64% | 2.5 | 10:19 |
| Dec | 85% | 72% | 1.9 | 9:52 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Hiroshima is like
The warmest month is August, with an average high of 32 °C89 °F and a low of 23 °C74 °F. The coldest is January, when highs average 8 °C46 °F and lows 0 °C32 °F. Seasons are strongly marked: the warmest month is on average 23.6 °C42.5 °F warmer than the coldest.
It is wet, with about 1,556 mm61 in of precipitation per year. The wettest three-month stretch is May–July, which brings 40% of the annual total. The wettest month is July (260 mm10 in), the driest is January (63 mm2.5 in).
Relative humidity ranges from 78% in April to 86% in July. The clearest skies (lowest average cloud amount, 63%) are typical of October. Average wind speed near the ground ranges from 6 km/h (4 mph) in June to 9 km/h (6 mph) in March. Daylight lasts from about 9.9 hours in December to 14.4 hours in June.
Best time to visit Hiroshima
Based on these averages, the most comfortable months for sightseeing and outdoor activities are October: average highs of 22 °C72 °F to 22 °C72 °F with 113 mm4.4 in to 113 mm4.4 in of precipitation per month.
The most challenging month is July, which is hot, with average highs of 30 °C87 °F, very wet (260 mm10 in) and humid (86% relative humidity).
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Hiroshima
- Winter (December–February) — highs 846 to 10 °C50 °F, lows 032 to 2 °C36 °F, about 74 mm2.9 in of precipitation a month. Pack a warm coat, layers and closed shoes.
- Spring (March–May) — highs 1456 to 24 °C75 °F, lows 337 to 13 °C56 °F, about 127 mm5.0 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket, an extra layer for the cooler mornings and evenings and an umbrella or light rain jacket.
- Summer (June–August) — highs 2781 to 32 °C89 °F, lows 1865 to 23 °C74 °F, about 198 mm7.8 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an umbrella or light rain jacket.
- Autumn (September–November) — highs 1661 to 28 °C82 °F, lows 745 to 19 °C67 °F, about 120 mm4.7 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an umbrella or light rain jacket.
How Hiroshima compares
Compared with Fukuoka, about 207 km to the southwest, Hiroshima is on average 0.7 °C1.3 °F cooler and receives 18% less precipitation (1,556 mm61 in vs 1,901 mm75 in). The difference is largest in February (1.3 °C2.4 °F cooler).
Of the 111 places in Japan covered by World Climates, Hiroshima is the 51st warmest by annual mean temperature and the 69th wettest by annual precipitation. See all of them on the Japan climate page.
Places in other countries with the most similar temperature and rainfall pattern: Virginia Beach (United States, Cfa), Norfolk (United States, Cfa) and East Hampton (United States, Cfa).
The same NASA POWER grid cell also contains Higashihiroshima (pop. 196,608) and Hatsukaichi (pop. 114,173). Their long-term averages in this dataset are essentially the same as for Hiroshima, so they do not have separate pages.
Nearby places
- Kure 22 km · 16 °C61 °F · 1,621 mm64 in
- Imabari 62 km · 17 °C62 °F · 1,699 mm67 in
- Shunan 67 km · 15 °C58 °F · 1,696 mm67 in
- Matsuyama 69 km · 17 °C62 °F · 1,621 mm64 in
- Fukuyama 85 km · 16 °C61 °F · 1,526 mm60 in
- Niihama 93 km · 17 °C62 °F · 1,699 mm67 in
- Yamaguchi 93 km · 15 °C60 °F · 1,821 mm72 in
- Shinagawa 99 km · 14 °C57 °F · 2,059 mm81 in
Frequently asked questions
What is the warmest month in Hiroshima?
August is the warmest month in Hiroshima, with an average high of 32 °C (89 °F) and an average low of 23 °C (74 °F).
What is the coldest month in Hiroshima?
January is the coldest month, with an average high of 8 °C (46 °F) and an average low of 0 °C (32 °F).
When does it rain the most in Hiroshima?
July is the wettest month with about 260 mm (10.2 in) of precipitation; January is the driest with about 63 mm (2.5 in).
What is the best time to visit Hiroshima?
Judging by long-term averages, the most comfortable months are October.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 329 m, while Hiroshima lies at about 16 m. Temperatures on this page were therefore adjusted by +2 °C3.7 °F using the standard lapse rate of 6.5 °C per 1,000 m.