Climate averages 1991–2020
Niihama 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 Niihama: daytime highs average 18.5°C and nights cool to about 10.4°C. By daytime temperature it is the 7th warmest of the 12 months.
Expect about 134 mm of rain on roughly 12 days, which makes April a wet month (the 6th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 01 min on an average April day.
The nearest other city in this atlas is Saijō (12 km away). In April its highs average 19.3°C, 0.8°C warmer than Niihama, with 134 mm of rain.
Among the 303 cities listed in Japan, Niihama ranks joint 30th of 303 for the warmest April highs and joint 199th of 303 for the driest April (rainfall, lowest first). The mean April high of those 303 cities is 16.7°C; Niihama is 1.8°C warmer than that mean.
From April to May, average highs rise by 4.3°C to 22.8°C, and monthly rainfall rises from 134 mm to 158 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
Niihama climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 9.0°C3.3°C | 3.3°C | 78 | 13.5 | 10.210 h |
| February | 10.1°C3.3°C | 3.3°C | 86 | 12.3 | 10.911 h |
| March | 13.6°C5.8°C | 5.8°C | 122 | 13.4 | 12.012 h |
| April, selected | 18.5°C10.4°C | 10.4°C | 134 | 11.6 | 13.013 h |
| May | 22.8°C15.1°C | 15.1°C | 158 | 11.2 | 13.914 h |
| June | 25.8°C19.5°C | 19.5°C | 249 | 15.1 | 14.414 h |
| July | 29.5°C23.9°C | 23.9°C | 228 | 15.6 | 14.214 h |
| August | 30.6°C24.8°C | 24.8°C | 151 | 13.8 | 13.413 h |
| September | 27.1°C21.4°C | 21.4°C | 216 | 14.1 | 12.412 h |
| October | 21.9°C15.7°C | 15.7°C | 166 | 11.0 | 11.411 h |
| November | 16.6°C10.2°C | 10.2°C | 90 | 9.9 | 10.410 h |
| December | 11.4°C5.5°C | 5.5°C | 90 | 12.8 | 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
April in nearby cities
- Saijō in AprilJapan · 12 kmHigh 19.3°C · Low 10.6°C · 134 mm rain
- Shikokuchūō in AprilJapan · 23 kmHigh 18.6°C · Low 10.2°C · 142 mm rain
- Imabari in AprilJapan · 31 kmHigh 17.5°C · Low 11.0°C · 132 mm rain
- Shinagawa in AprilJapan · 45 kmHigh 18.0°C · Low 8.6°C · 146 mm rain
- Kochi in AprilJapan · 50 kmHigh 18.8°C · Low 9.2°C · 203 mm rain
- Matsuyama in AprilJapan · 52 kmHigh 18.7°C · Low 10.3°C · 133 mm rain
- Onomichi in AprilJapan · 52 kmHigh 17.9°C · Low 8.9°C · 107 mm rain
- Mihara in AprilJapan · 53 kmHigh 18.4°C · Low 8.9°C · 110 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 Niihama) is explained once on the Niihama year overview and on the Sources, method and limits page.
Saijō lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.