Niihama climate — normals and trends
Niihama (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 15.1 °C and it receives 1,750 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is August (26.2 °C on average) and the coldest is January (4.5 °C). Rainfall peaks in June.
Niihama averages 15 frost days, 14 hot days (≥ 30 °C) and 165 rainy days per year.
Niihama has warmed by +1.9 °C between 1940 and 2025, or +0.22 °C per decade. This trend is statistically significant.
The number of frost days there went from about 26 to 4 per year over the period.
The hottest day of the period reached 33.1 °C (on 16 July 1994) and the coldest -6.7 °C (on 27 February 1981).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
NiihamaEhime
- coords
- 33.96°, 133.31°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
15.1°C
Average daily high
17.8°C
Average daily low
12.5°C
Annual rainfall
1,750mm
Sunshine / day
9.0h
Mean relative humidity
75%
Average peak wind
14.6km/h
Seasonal range
21.7°C
Frost days (< 0 °C)
15 d/yr
Hot days (≥ 30 °C)
14 d/yr
Rainy days (≥ 1 mm)
165 d/yr
Annual snowfall
23.9 cm
Average feels-like high
17.7 °C
Average feels-like low
11.7 °C
Average peak gust
34.4 km/h
Tropical nights (≥ 20 °C)
90 d/yr
Solar radiation
14.9 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.9 °C
since 1940
+0.2 °C per decade · r² = 0.65 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
33.1 °C
16 July 1994
Coldest day
-6.7 °C
27 February 1981
Wettest day
180 mm
29 September 2004
Windiest day
61.0 km/h
7 September 2004
Strongest gust
168.8 km/h
7 September 2004
Hottest feels-like
40.1 °C
22 August 2024
Coldest feels-like
-13.4 °C
26 February 1981
Snowiest day
23.6 cm
15 February 1968
Sunniest day
14.0 h
10 June 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 7.0 °C | +0.1 °C | 47 mm | -32 mm |
| Feb | 6.0 °C | -1.6 °C | 59 mm | -29 mm |
| Mar | 11.9 °C | +0.7 °C | 116 mm | +3 mm |
| Apr | 17.0 °C | +0.5 °C | 80 mm | -58 mm |
| May | 20.5 °C | +0.1 °C | 230 mm | +68 mm |
| Jun | 25.4 °C | +1.7 °C | 328 mm | +79 mm |
| Jul | 30.3 °C | +2.7 °C | 68 mm | -152 mm |
| Aug | 30.5 °C | +1.7 °C | 169 mm | +6 mm |
| Sep | 28.1 °C | +2.6 °C | 215 mm | -5 mm |
| Oct | 22.4 °C | +2.3 °C | 215 mm | +71 mm |
| Nov | 15.7 °C | +0.7 °C | 43 mm | -53 mm |
| Dec | 11.1 °C | +1.4 °C | 53 mm | -26 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Niihama?
Niihama has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 15.1 °C and it receives 1,750 mm of precipitation per year.
What is the hottest day ever recorded in Niihama?
The hottest day measured in Niihama between 1940 and 2025 was 16 July 1994, reaching 33.1 °C.
What is the coldest day in Niihama?
The coldest day measured in Niihama between 1940 and 2025 was 27 February 1981, at -6.7 °C.
Does it snow in Niihama?
Yes. Niihama gets on average 23.9 cm of snow per year and has around 15 frost days.
Has the climate of Niihama warmed?
Yes: Niihama warmed by +1.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Niihama?
The wettest day measured in Niihama between 1940 and 2025 was 29 September 2004, with 180 mm of rain in 24 hours.
What was the windiest day in Niihama?
The windiest day measured in Niihama between 1940 and 2025 was 7 September 2004, with winds reaching 61.0 km/h.
What is the warmest month in Niihama?
The warmest month in Niihama is August (26.2 °C on average); the coldest is January (4.5 °C).
How much does it rain in Niihama?
Niihama receives on average 1,750 mm of precipitation per year, spread over about 165 rainy days.
Is it sunny in Niihama?
Niihama gets on average 9.0 hours of sunshine per day, roughly 3,285 hours per year over 1940-2025.
What is the biggest single-day snowfall in Niihama?
The heaviest 24-hour snowfall measured in Niihama between 1940 and 2025 was 15 February 1968, with 23.6 cm.
Are there tropical nights in Niihama?
Yes: Niihama has on average 90 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Niihama?
In Niihama, between 1940 and 2025, the highest apparent temperature reached 40.1 °C on 22 August 2024, and the lowest was -13.4 °C on 26 February 1981.
Compare Niihama with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Niihama