Climate averages 1991–2020
Niiza weather
in April.
A mild, wet month: the 7th warmest and the 6th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
April is a mild month in Niiza: daytime highs average 17.5°C and nights cool to about 7.9°C. By daytime temperature it is the 7th warmest of the 12 months.
Expect about 123 mm of rain on roughly 13 days, which makes April a wet month (the 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 05 min on an average April day.
The nearest other city in this atlas is Tokorozawa (8 km away). In April its highs average 16.9°C, 0.6°C cooler than Niiza, with 123 mm of rain.
Among the 303 cities listed in Japan, Niiza ranks joint 136th of 303 for the warmest April highs and joint 142nd of 303 for the driest April (rainfall, lowest first). The mean April high of those 303 cities is 16.7°C; Niiza is 0.7°C warmer than that mean.
From April to May, average highs rise by 4.6°C to 22.0°C, and monthly rainfall rises from 123 mm to 139 mm.
The annual picture
April 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
Niiza climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 7.9°C-1.6°C | -1.6°C | 69 | 7.5 | 10.010 h |
| February | 8.9°C-0.9°C | -0.9°C | 66 | 8.5 | 10.911 h |
| March | 12.4°C2.7°C | 2.7°C | 120 | 13.2 | 11.912 h |
| April, selected | 17.5°C7.9°C | 7.9°C | 123 | 12.8 | 13.113 h |
| May | 22.0°C13.4°C | 13.4°C | 139 | 13.1 | 14.014 h |
| June | 24.8°C17.7°C | 17.7°C | 177 | 15.4 | 14.515 h |
| July | 28.5°C21.8°C | 21.8°C | 182 | 16.4 | 14.314 h |
| August | 29.9°C23.2°C | 23.2°C | 142 | 15.4 | 13.514 h |
| September | 26.0°C19.6°C | 19.6°C | 204 | 14.9 | 12.412 h |
| October | 20.5°C13.5°C | 13.5°C | 215 | 13.7 | 11.311 h |
| November | 15.3°C7.2°C | 7.2°C | 92 | 10.2 | 10.310 h |
| December | 10.3°C1.4°C | 1.4°C | 61 | 7.4 | 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
April in nearby cities
- Tokorozawa in AprilJapan · 8 kmHigh 16.9°C · Low 7.1°C · 123 mm rain
- Yono in AprilJapan · 10 kmHigh 17.6°C · Low 7.6°C · 105 mm rain
- Kawagoe in AprilJapan · 12 kmHigh 17.4°C · Low 7.2°C · 106 mm rain
- Musashino in AprilJapan · 13 kmHigh 16.9°C · Low 8.2°C · 123 mm rain
- Saitama in AprilJapan · 13 kmHigh 17.8°C · Low 7.9°C · 105 mm rain
- Sayama in AprilJapan · 14 kmHigh 17.2°C · Low 6.8°C · 123 mm rain
- Kawaguchi in AprilJapan · 14 kmHigh 17.7°C · Low 8.3°C · 113 mm rain
- Iruma in AprilJapan · 17 kmHigh 16.8°C · Low 6.8°C · 146 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 Niiza) is explained once on the Niiza year overview and on the Sources, method and limits page.
Tokorozawa, Fuchū and Hino lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.