Climate averages 1991–2020
Shūnan weather
by month.
See how the year changes. August has the highest average daily maximum; January has the lowest average monthly rainfall.
Pleasant-weather months by our simple rule: October
Long-term climate patterns, not a forecast for a particular trip.
Across the year Shūnan averages a daytime high of 17.5°C and a nighttime low of 10.9°C, with about 1,679 mm of rain on roughly 129 days. August is the warmest month (average high 28.3°C) and January the coolest (6.6°C). June is the wettest month with 264 mm; January is the driest with 61 mm.
Months with pleasant weather by a simple rule (average high between 18°C and 29°C, average low of at least 5°C and at most 8 rain days): October. This looks at temperature and rain only, not humidity, wind, sea temperature or crowds.
The annual picture
A year in Shūnan
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Shūnan climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 6.6°C0.8°C | 0.8°C | 61 | 9.3 | 10.210 h |
| February | 7.8°C0.8°C | 0.8°C | 78 | 9.7 | 10.911 h |
| March | 11.3°C3.4°C | 3.4°C | 124 | 10.7 | 12.012 h |
| April | 16.2°C7.9°C | 7.9°C | 147 | 10.2 | 13.013 h |
| May | 20.5°C12.8°C | 12.8°C | 169 | 10.1 | 13.914 h |
| June | 23.6°C17.2°C | 17.2°C | 264 | 14.3 | 14.414 h |
| July | 27.1°C21.5°C | 21.5°C | 259 | 14.6 | 14.214 h |
| August | 28.3°C22.6°C | 22.6°C | 147 | 12.7 | 13.413 h |
| September | 25.1°C19.0°C | 19.0°C | 169 | 11.5 | 12.412 h |
| October | 20.1°C13.4°C | 13.4°C | 113 | 7.7 | 11.411 h |
| November | 14.5°C8.0°C | 8.0°C | 78 | 8.1 | 10.410 h |
| December | 8.9°C3.0°C | 3.0°C | 69 | 9.8 | 9.910 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
Nearby cities
- HōfuJapan · 24 kmHigh 19.5°C · Low 12.6°C · 1,617 mm rain a year
- YamaguchiJapan · 35 kmHigh 19.0°C · Low 11.4°C · 1,644 mm rain a year
- IwakuniJapan · 37 kmHigh 19.1°C · Low 12.8°C · 1,621 mm rain a year
- UbeJapan · 55 kmHigh 18.9°C · Low 13.5°C · 1,690 mm rain a year
- HatsukaichiJapan · 55 kmHigh 19.7°C · Low 12.2°C · 1,621 mm rain a year
- HiroshimaJapan · 67 kmHigh 19.3°C · Low 11.6°C · 1,554 mm rain a year
- KureJapan · 70 kmHigh 18.0°C · Low 13.1°C · 1,502 mm rain a year
- NakatsuJapan · 80 kmHigh 19.9°C · Low 12.9°C · 1,574 mm rain a year
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsWhat do the high and low temperatures mean?
We average the daily maximum and daily minimum for each calendar month over 1991–2020. They are not record extremes, a forecast range or temperatures at a fixed time of day.
How is a rain day counted?
A local calendar day (standard time, UTC+9, no daylight saving) with at least 1 mm of total precipitation counts as one rain day. We count these for each year and month, then average across 30 years. The average does not predict which days will be wet.
Where do the numbers come from?
ERA5-Land (temperature) and ERA5 (precipitation) reanalysis from the Copernicus Climate Change Service, read from the Open-Meteo open-data archive. Temperature comes from the 0.1° model cell at 34.10°, 131.80° (3 km from the city centre), adjusted down by 0.6°C for the difference between the city's elevation (316 m) and the cell's (221 m). Rain comes from the 0.25° cell at 34.00°, 131.75°. These are model estimates, not weather-station readings; coast, hills and city streets can differ.
Does this page show sunshine, humidity or sea temperature?
No. The data used here contain air temperature and precipitation only. Daylight hours are calculated from the city's latitude (sunrise to sunset), not measured sunshine.