Yamaguchi climate
Yamaguchi (Japan) has a humid subtropical climate (Köppen Cfa). The average temperature over the year is 15 °C60 °F, and about 1,821 mm72 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Yamaguchi climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | 846 | 236 | 541 | 763.0 | 4 |
| Feb | 949 | 236 | 643 | 853.4 | 4 |
| Mar | 1355 | 440 | 847 | 1204.7 | 1 |
| Apr | 1864 | 847 | 1355 | 1395.5 | 0 |
| May | 2272 | 1356 | 1864 | 1566.1 | 0 |
| Jun | 2578 | 1864 | 2271 | 26610 | 0 |
| Jul | 2984 | 2272 | 2678 | 33013 | 0 |
| Aug | 3086 | 2374 | 2780 | 1807.1 | 0 |
| Sep | 2680 | 2067 | 2373 | 1947.6 | 0 |
| Oct | 2170 | 1457 | 1864 | 1084.3 | 0 |
| Nov | 1660 | 948 | 1254 | 843.3 | 0 |
| Dec | 1050 | 440 | 745 | 843.3 | 1 |
| Year | 3086 | 236 | 1560 | 1,82172 | 9 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 77% | 86% | 1.9 | 10:06 |
| Feb | 77% | 81% | 2.7 | 10:55 |
| Mar | 76% | 75% | 3.8 | 11:53 |
| Apr | 77% | 69% | 4.8 | 12:00 |
| May | 78% | 68% | 5.3 | 13:56 |
| Jun | 83% | 80% | 4.7 | 14:25 |
| Jul | 84% | 76% | 4.7 | 14:13 |
| Aug | 82% | 68% | 5.0 | 13:25 |
| Sep | 83% | 73% | 4.0 | 12:20 |
| Oct | 80% | 68% | 3.4 | 11:15 |
| Nov | 78% | 74% | 2.4 | 10:20 |
| Dec | 78% | 83% | 1.8 | 9:53 |
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 Yamaguchi is like
The warmest month is August, with an average high of 30 °C86 °F and a low of 23 °C74 °F. The coldest is January, when highs average 8 °C46 °F and lows 2 °C36 °F. Seasons are strongly marked: the warmest month is on average 21.6 °C38.9 °F warmer than the coldest.
It is wet, with about 1,821 mm72 in of precipitation per year. The wettest three-month stretch is June–August, which brings 43% of the annual total. The wettest month is July (330 mm13 in), the driest is January (76 mm3.0 in).
Relative humidity ranges from 76% in March to 84% in July. The clearest skies (lowest average cloud amount, 68%) are typical of August. Average wind speed near the ground ranges from 4 km/h (3 mph) in July to 8 km/h (5 mph) in January. Daylight lasts from about 9.9 hours in December to 14.4 hours in June.
Best time to visit Yamaguchi
Based on these averages, the most comfortable months for sightseeing and outdoor activities are October: average highs of 21 °C70 °F to 21 °C70 °F with 108 mm4.3 in to 108 mm4.3 in of precipitation per month.
The most challenging month is July, which is very wet (330 mm13 in) and humid (84% 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 Yamaguchi
- Winter (December–February) — highs 846 to 10 °C50 °F, lows 236 to 4 °C40 °F, about 82 mm3.2 in of precipitation a month. Pack a warm coat, layers and closed shoes.
- Spring (March–May) — highs 1355 to 22 °C72 °F, lows 440 to 13 °C56 °F, about 138 mm5.4 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket and an umbrella or light rain jacket.
- Summer (June–August) — highs 2578 to 30 °C86 °F, lows 1864 to 23 °C74 °F, about 259 mm10 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and a good rain jacket or umbrella and quick-drying shoes.
- Autumn (September–November) — highs 1660 to 26 °C80 °F, lows 948 to 20 °C67 °F, about 129 mm5.1 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket and an umbrella or light rain jacket.
How Yamaguchi compares
Compared with Kitakyushu, about 68 km to the southwest, Yamaguchi is on average 1.5 °C2.7 °F cooler and receives a similar amount of precipitation. The difference is largest in December (2.5 °C4.6 °F cooler).
Of the 111 places in Japan covered by World Climates, Yamaguchi is the 52nd warmest by annual mean temperature and the 33rd 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: Ulsan (South Korea, Cfa), Virginia Beach (United States, Cfa) and Norfolk (United States, Cfa).
Nearby places
- Ube 33 km · 16 °C61 °F · 1,821 mm72 in
- Shunan 35 km · 15 °C58 °F · 1,696 mm67 in
- Kitakyushu 68 km · 17 °C62 °F · 1,860 mm73 in
- Hiroshima 93 km · 15 °C60 °F · 1,556 mm61 in
- Beppu 101 km · 17 °C63 °F · 1,939 mm76 in
- Kure 101 km · 16 °C61 °F · 1,621 mm64 in
- Ōita 106 km · 18 °C64 °F · 2,027 mm80 in
- Fukuoka 117 km · 16 °C61 °F · 1,901 mm75 in
Frequently asked questions
What is the warmest month in Yamaguchi?
August is the warmest month in Yamaguchi, with an average high of 30 °C (86 °F) and an average low of 23 °C (74 °F).
What is the coldest month in Yamaguchi?
January is the coldest month, with an average high of 8 °C (46 °F) and an average low of 2 °C (36 °F).
When does it rain the most in Yamaguchi?
July is the wettest month with about 330 mm (13.0 in) of precipitation; January is the driest with about 76 mm (3.0 in).
What is the best time to visit Yamaguchi?
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 107 m, while Yamaguchi lies at about 157 m. Temperatures on this page were therefore adjusted by −0.3 °C0.6 °F using the standard lapse rate of 6.5 °C per 1,000 m.