Climate averages 1991–2020
Iruma weather
in June.
A warm, very wet month: the 4th warmest and the 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
June is a warm month in Iruma: daytime highs average 23.8°C and nights cool to about 16.7°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 222 mm of rain on roughly 20 days, which makes June a very wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 33 min on an average June day.
The nearest other city in this atlas is Sayama (6 km away). In June its highs average 24.2°C, about as warm as Iruma, with 177 mm of rain.
Among the 303 cities listed in Japan, Iruma ranks joint 218th of 303 for the warmest June highs and joint 210th of 303 for the driest June (rainfall, lowest first). The mean June high of those 303 cities is 24.4°C; Iruma is 0.6°C cooler than that mean.
From June to July, average highs rise by 3.7°C to 27.5°C, and monthly rainfall rises from 222 mm to 243 mm.
The annual picture
June in context
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
Iruma climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 7.2°C-2.7°C | -2.7°C | 77 | 8.5 | 10.010 h |
| February | 8.1°C-2.0°C | -2.0°C | 76 | 9.7 | 10.911 h |
| March | 11.7°C1.5°C | 1.5°C | 139 | 15.2 | 11.912 h |
| April | 16.8°C6.8°C | 6.8°C | 146 | 14.6 | 13.113 h |
| May | 21.2°C12.3°C | 12.3°C | 166 | 15.6 | 14.014 h |
| June, selected | 23.8°C16.7°C | 16.7°C | 222 | 19.5 | 14.515 h |
| July | 27.5°C20.9°C | 20.9°C | 243 | 21.8 | 14.314 h |
| August | 28.7°C22.2°C | 22.2°C | 205 | 21.0 | 13.514 h |
| September | 25.0°C18.6°C | 18.6°C | 249 | 18.2 | 12.412 h |
| October | 19.6°C12.6°C | 12.6°C | 242 | 16.2 | 11.311 h |
| November | 14.6°C6.3°C | 6.3°C | 101 | 11.3 | 10.310 h |
| December | 9.7°C0.4°C | 0.4°C | 68 | 8.3 | 9.810 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
June in nearby cities
- Sayama in JuneJapan · 6 kmHigh 24.2°C · Low 16.9°C · 177 mm rain
- Hannō in JuneJapan · 6 kmHigh 24.5°C · Low 17.3°C · 222 mm rain
- Tokorozawa in JuneJapan · 9 kmHigh 24.0°C · Low 17.0°C · 177 mm rain
- Ōme in JuneJapan · 12 kmHigh 24.3°C · Low 17.2°C · 222 mm rain
- Kawagoe in JuneJapan · 15 kmHigh 24.5°C · Low 17.2°C · 162 mm rain
- Sakado in JuneJapan · 16 kmHigh 24.7°C · Low 17.4°C · 162 mm rain
- Akiruno in JuneJapan · 16 kmHigh 24.1°C · Low 17.1°C · 222 mm rain
- Hino in JuneJapan · 16 kmHigh 23.8°C · Low 17.0°C · 177 mm rain
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 limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Iruma) is explained once on the Iruma year overview and on the Sources, method and limits page.
Hachiōji, Ōme and Akiruno lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.