Tamba-Sasayama, Japan Climate
The warmest month is August, with an average high of 30°C; the coldest is January, with an average low of -1°C. A normal year brings 1523 mm of precipitation.
Temperature through the year
The normal daily high and low. The line marks today.
- Normal low
- Normal high
- Reanalysis extreme high
- Reanalysis extreme low
Normals for Sep 26
- Normal high
- 24°C
- Normal low
- 16°C
- Reanalysis high
- 28°Cin 2019
- Reanalysis low
- 12°Cin 1993
- Chance of a wet day
- 46%
- Daylight
- 12 h 01 min
Month by month
Averages for 1991-2020. Wet days have at least 1 mm of precipitation in the reanalysis. Each month links to its own page.
| Month | Avg high | Avg low | Warmest | Coldest | Precipitation | Wet days |
|---|---|---|---|---|---|---|
| January | 7°C | -1°C | 18°C (2002) | -7°C (2001) | 90 mm | 18.6 |
| February | 8°C | -1°C | 19°C (1992) | -8°C (2018) | 88 mm | 14.1 |
| March | 12°C | 1°C | 21°C (1998) | -5°C (2015) | 109 mm | 12.4 |
| April | 17°C | 6°C | 26°C (2005) | -3°C (1991) | 108 mm | 12.0 |
| May | 22°C | 11°C | 31°C (2014) | 1°C (1991) | 136 mm | 12.4 |
| June | 25°C | 16°C | 32°C (2005) | 8°C (1993) | 174 mm | 15.0 |
| July | 29°C | 21°C | 36°C (2014) | 14°C (1996) | 189 mm | 15.5 |
| August | 30°C | 22°C | 37°C (1994) | 15°C (2002) | 124 mm | 12.4 |
| September | 26°C | 18°C | 34°C (1994) | 8°C (1992) | 183 mm | 15.0 |
| October | 21°C | 12°C | 29°C (2013) | 3°C (1997) | 136 mm | 12.4 |
| November | 15°C | 6°C | 24°C (2011) | -2°C (2008) | 90 mm | 12.0 |
| December | 9°C | 1°C | 21°C (2018) | -5°C (2012) | 96 mm | 15.5 |
| Year | 18°C | 9°C | 1523 mm | 167 |
Precipitation
Rain and melted snow together. The chance of a wet day is the share of days with at least 1 mm of precipitation in the reanalysis.
1523 mm in a normal year, most in July.
Chance of a wet day
- Chance of a wet day
Humidity and comfort
NASA POWER reanalysis, 1991-2020, for the grid cell around Tamba-Sasayama.
The muggiest month is August, when 97 percent of days are muggy or worse, with a mean dew point of 18°C or more.
| Month | Dew point | Humidity | Dry | Comfortable | Humid | Muggy | Oppressive | Miserable |
|---|---|---|---|---|---|---|---|---|
| January | 0°C | 87% | 100% | 0% | 0% | 0% | 0% | 0% |
| February | 0°C | 84% | 100% | 0% | 0% | 0% | 0% | 0% |
| March | 3°C | 81% | 99% | 1% | 0% | 0% | 0% | 0% |
| April | 8°C | 80% | 87% | 11% | 2% | 0% | 0% | 0% |
| May | 13°C | 81% | 47% | 33% | 16% | 4% | 0% | 0% |
| June | 18°C | 84% | 5% | 19% | 37% | 27% | 12% | 0% |
| July | 22°C | 86% | 0% | 0% | 4% | 21% | 63% | 12% |
| August | 23°C | 84% | 0% | 0% | 2% | 15% | 58% | 24% |
| September | 19°C | 85% | 4% | 11% | 28% | 29% | 26% | 2% |
| October | 13°C | 84% | 48% | 28% | 16% | 7% | 1% | 0% |
| November | 7°C | 85% | 91% | 7% | 2% | 0% | 0% | 0% |
| December | 2°C | 87% | 100% | 0% | 0% | 0% | 0% | 0% |
Comfort is judged by the day's mean dew point: dry below 13°C, comfortable to 16°C, humid to 18°C, muggy to 21°C, oppressive to 24°C, miserable above.
Clouds
Average share of the sky covered, from satellite (CERES and GEWEX SRB) by way of NASA POWER, 1991-2020.
The clearest month is August, with the sky 66 percent covered on average; the cloudiest is January, at 84 percent.
Wind
The mean wind speed over the whole day, from the MERRA-2 reanalysis by way of NASA POWER. Gusts run well above it.
The windiest month is March, averaging 14.4 km/h at 10 meters (33 feet) above the ground.
Daylight and sunshine
The longest day is Jun 21, with 14 h 32 min of daylight; the shortest is Dec 16, with 9 h 48 min.
- Day length
Solar energy
Average daily sunshine reaching the ground on a flat surface, in kilowatt-hours per square meter, clouds included.
Month pages
The weather in Tamba-Sasayama in each month, day by day.
What this means
A normal is the average of the thirty years 1991 to 2020, the period the World Meteorological Organization and NOAA use for comparison. It is an average, not a forecast: most days depart from it, and some by a long way.
Where no station record is within reach, the extremes shown are the highest and lowest the reanalysis produced for the date in 1991-2020, not measured records.
Cloud, humidity, wind and sunshine come from a reanalysis: a weather model run over the past with every observation fed in, averaged over a grid cell about 50 km across. It is consistent everywhere on Earth; it smooths local detail such as a lake shore or a valley.
More for this place
Nearby
Sources
Cloud, humidity, wind and sunshine, and temperature and precipitation: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.