Yamaguchi climate
Yamaguchi is warmest in August, with average highs of 30 °C, and coldest in January, when nights average 1.6 °C. July is the wettest month (294 mm) and January the driest (63 mm). Figures are 1991–2020 climate normals.
Across a full year Yamaguchi averages 1,692 mm of rain, 106 days above 25 °C and 20 days below freezing.
Japan · population 193,966 · 1991–2020 normals
Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month
- Warmest month August 30 °C
- Coldest month January 1.6 °C
- Driest month January 63 mm
- Wettest month July 294 mm
- Least cloud October 50 % cloud
- Hottest on record August 37 °C
- Coldest on record February -6.2 °C
What to expectYamaguchi through the year
Yamaguchi has a clear annual cycle: average daily highs run from 7.6 °C in January to 30 °C in August, a swing of 22 °C in mean temperature across the year.
Counted across a normal year, 106 days a year reach 25 °C, 32 of them reach 30 °C, 20 nights drop below freezing. The warmest reading in the 1991–2020 record is 37 °C, in August.
Rain is strongly seasonal. July averages 294 mm against 63 mm in January — 4.7 times as much. Planning around the dry months matters more here than planning around temperature.
Month by month
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | 7.6 °C | 63 mm | 64 % |
| February | 9.0 °C | 73 mm | 63 % |
| March | 12.6 °C | 119 mm | 61 % |
| April | 17.9 °C | 135 mm | 60 % |
| May | 22.4 °C | 148 mm | 63 % |
| June | 25.5 °C | 261 mm | 78 % |
| July | 28.8 °C | 294 mm | 73 % |
| August | 30.2 °C | 176 mm | 63 % |
| September | 26.7 °C | 184 mm | 62 % |
| October | 21.5 °C | 98 mm | 50 % |
| November | 15.7 °C | 77 mm | 53 % |
| December | 9.9 °C | 65 mm | 59 % |
Temperature month by month
| Month | Avg high | Avg low | Mean | Record high | Record low | Days above 25 °C | Days above 30 °C | Days below 0 °C |
|---|---|---|---|---|---|---|---|---|
| January | 7.6 °C | 1.6 °C | 4.3 °C | 16.5 °C | -5.2 °C | 0 | 0 | 8 |
| February | 9.0 °C | 1.9 °C | 5.1 °C | 19.1 °C | -6.2 °C | 0 | 0 | 8 |
| March | 12.6 °C | 4.4 °C | 8.2 °C | 21.5 °C | -3.1 °C | 0 | 0 | 2 |
| April | 17.9 °C | 9.0 °C | 13.1 °C | 26.9 °C | -0.1 °C | 0 | 0 | 0 |
| May | 22.4 °C | 13.6 °C | 17.6 °C | 30.6 °C | 4.4 °C | 5 | 0 | 0 |
| June | 25.5 °C | 18.2 °C | 21.5 °C | 32.9 °C | 10.3 °C | 18 | 1 | 0 |
| July | 28.8 °C | 22.4 °C | 25.2 °C | 36.8 °C | 15.1 °C | 28 | 11 | 0 |
| August | 30.2 °C | 23.3 °C | 26.2 °C | 36.9 °C | 16.6 °C | 31 | 17 | 0 |
| September | 26.7 °C | 19.5 °C | 22.6 °C | 34.5 °C | 11.7 °C | 21 | 3 | 0 |
| October | 21.5 °C | 13.7 °C | 17.1 °C | 28.9 °C | 4.5 °C | 4 | 0 | 0 |
| November | 15.7 °C | 8.5 °C | 11.7 °C | 24.7 °C | -1.2 °C | 0 | 0 | 0 |
| December | 9.9 °C | 3.7 °C | 6.5 °C | 18.8 °C | -4.0 °C | 0 | 0 | 2 |
Rain, sun and wind month by month
| Month | Rainfall | Wet days | Daylight | Cloud cover | Humidity | Wind |
|---|---|---|---|---|---|---|
| January | 63 mm | 10 | 10 h/day | 64 % | 74 % | 16 km/h |
| February | 73 mm | 9 | 11 h/day | 63 % | 73 % | 16 km/h |
| March | 119 mm | 12 | 12 h/day | 61 % | 73 % | 16 km/h |
| April | 135 mm | 11 | 13 h/day | 60 % | 74 % | 16 km/h |
| May | 148 mm | 10 | 14 h/day | 63 % | 76 % | 15 km/h |
| June | 261 mm | 15 | 14 h/day | 78 % | 83 % | 13 km/h |
| July | 294 mm | 16 | 14 h/day | 73 % | 86 % | 14 km/h |
| August | 176 mm | 15 | 13 h/day | 63 % | 83 % | 14 km/h |
| September | 184 mm | 12 | 12 h/day | 62 % | 81 % | 14 km/h |
| October | 98 mm | 8 | 11 h/day | 50 % | 77 % | 13 km/h |
| November | 77 mm | 8 | 10 h/day | 53 % | 77 % | 14 km/h |
| December | 65 mm | 10 | 9.9 h/day | 59 % | 75 % | 16 km/h |
How Yamaguchi compares
The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.
| Destination | Summer high | Winter low | Rain per year | Days above 25 °C |
|---|---|---|---|---|
| Yamaguchi | 30 °C | 1.6 °C | 1,692 mm | 106 |
| Ube · Japan | 30 °C | 4.2 °C | 1,701 mm | 97 |
| Shimonoseki · Japan | 30 °C | 3.7 °C | 1,639 mm | 100 |
| Kitakyushu · Japan | 30 °C | 3.4 °C | 1,560 mm | 101 |
| Hiroshima · Japan | 30 °C | 1.6 °C | 1,563 mm | 110 |
Planning a trip? See the best time to visit Yamaguchi.
QuestionsCommon questions about Yamaguchi’s climate
When is the best time to visit Yamaguchi?
That depends on what you want, so the honest answer is a comparison rather than a single month. May, June, September sit closest to 20 °C on average, August is the warmest month and January the driest. The month-by-month table above has the full picture.
How hot does Yamaguchi get?
In August, the warmest month, daily highs average 30 °C. About 32 days a year pass 30 °C. The highest value in the 1991–2020 record is 37 °C.
How cold does it get in winter?
Nights average 1.6 °C in January, the coldest month. A normal year has 20 nights below freezing.
Which month is wettest in Yamaguchi?
July, averaging 294 mm over 16 days with rain. The driest month is January with 63 mm. The year as a whole averages 1,692 mm.
Are these figures a forecast?
No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Yamaguchi rather than what any particular week will bring. Individual years can differ substantially from the normal.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.