Climate averages 1991–2020
Niihama weather
in January.
A cool, moderately wet month: the coolest and the driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
January is a cool month in Niihama: daytime highs average 9.0°C and nights cool to about 3.3°C. By daytime temperature it is the coolest month of the year.
Expect about 78 mm of rain on roughly 14 days, which makes January a moderately wet month (the driest month of the year). Daylight, from sunrise to sunset, lasts about 10 h 10 min on an average January day.
The nearest other city in this atlas is Saijō (12 km away). In January its highs average 8.8°C, about as warm as Niihama, with 78 mm of rain.
Among the 303 cities listed in Japan, Niihama ranks joint 42nd of 303 for the warmest January highs and joint 218th of 303 for the driest January (rainfall, lowest first). The mean January high of those 303 cities is 7.0°C; Niihama is 2.1°C warmer than that mean.
From January to February, average highs rise by 1.1°C to 10.1°C, and monthly rainfall rises from 78 mm to 86 mm.
The annual picture
January 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, selected | 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 | 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
January in nearby cities
- Saijō in JanuaryJapan · 12 kmHigh 8.8°C · Low 3.0°C · 78 mm rain
- Shikokuchūō in JanuaryJapan · 23 kmHigh 8.7°C · Low 2.9°C · 80 mm rain
- Imabari in JanuaryJapan · 31 kmHigh 8.5°C · Low 4.1°C · 66 mm rain
- Shinagawa in JanuaryJapan · 45 kmHigh 7.1°C · Low 0.6°C · 71 mm rain
- Kochi in JanuaryJapan · 50 kmHigh 9.5°C · Low 2.1°C · 72 mm rain
- Matsuyama in JanuaryJapan · 52 kmHigh 8.8°C · Low 3.1°C · 69 mm rain
- Onomichi in JanuaryJapan · 52 kmHigh 8.5°C · Low 1.5°C · 42 mm rain
- Mihara in JanuaryJapan · 53 kmHigh 8.7°C · Low 1.4°C · 43 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.