Gero climate — normals and trends
Gero (Japan) has a hot-summer humid continental climate (Dfa) under the Köppen-Geiger classification. Its mean annual temperature is 10.4 °C and it receives 2,358 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 (22.6 °C on average) and the coldest is January (-2.4 °C). Rainfall peaks in July.
Gero averages 111 frost days, 7 hot days (≥ 30 °C) and 183 rainy days per year.
Gero has warmed by +3.3 °C between 1940 and 2025, or +0.39 °C per decade. This trend is statistically significant.
The number of frost days there went from about 137 to 85 per year over the period.
The hottest day of the period reached 35.6 °C (on 24 July 2018) and the coldest -22.3 °C (on 22 January 1942).
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
GeroGifu
- coords
- 35.80°, 137.23°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
10.4°C
Average daily high
15.0°C
Average daily low
6.1°C
Annual rainfall
2,358mm
Sunshine / day
8.4h
Mean relative humidity
75%
Average peak wind
11.0km/h
Seasonal range
25.0°C
Frost days (< 0 °C)
111 d/yr
Hot days (≥ 30 °C)
7 d/yr
Rainy days (≥ 1 mm)
183 d/yr
Annual snowfall
103.5 cm
Average feels-like high
14.0 °C
Average feels-like low
4.4 °C
Average peak gust
38.5 km/h
Tropical nights (≥ 20 °C)
19 d/yr
Solar radiation
14.3 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+3.3 °C
since 1940
+0.4 °C per decade · r² = 0.70 · 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
35.6 °C
24 July 2018
Coldest day
-22.3 °C
22 January 1942
Wettest day
186 mm
3 June 1988
Windiest day
55.0 km/h
26 September 1959
Strongest gust
213.8 km/h
26 September 1959
Hottest feels-like
39.3 °C
30 July 2025
Coldest feels-like
-27.2 °C
22 January 1942
Snowiest day
27.0 cm
15 February 2014
Sunniest day
14.0 h
11 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 | 3.1 °C | +0.8 °C | 74 mm | -17 mm |
| Feb | 2.2 °C | -1.2 °C | 76 mm | -25 mm |
| Mar | 10.2 °C | +2.5 °C | 178 mm | +15 mm |
| Apr | 16.4 °C | +2.1 °C | 151 mm | -50 mm |
| May | 20.5 °C | +1.5 °C | 257 mm | +42 mm |
| Jun | 24.8 °C | +2.8 °C | 333 mm | +25 mm |
| Jul | 29.5 °C | +3.9 °C | 200 mm | -165 mm |
| Aug | 29.7 °C | +2.7 °C | 247 mm | +6 mm |
| Sep | 26.3 °C | +2.9 °C | 283 mm | +15 mm |
| Oct | 19.4 °C | +1.6 °C | 213 mm | +31 mm |
| Nov | 12.2 °C | +0.4 °C | 72 mm | -54 mm |
| Dec | 6.9 °C | +1.5 °C | 120 mm | +22 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 Gero?
Gero has a hot-summer humid continental climate (Köppen Dfa). Over 1940-2025, the average annual temperature is 10.4 °C and it receives 2,358 mm of precipitation per year.
What is the hottest day ever recorded in Gero?
The hottest day measured in Gero between 1940 and 2025 was 24 July 2018, reaching 35.6 °C.
What is the coldest day in Gero?
The coldest day measured in Gero between 1940 and 2025 was 22 January 1942, at -22.3 °C.
Does it snow in Gero?
Yes. Gero gets on average 103.5 cm of snow per year and has around 111 frost days.
Has the climate of Gero warmed?
Yes: Gero warmed by +3.3 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Gero?
The wettest day measured in Gero between 1940 and 2025 was 3 June 1988, with 186 mm of rain in 24 hours.
What was the windiest day in Gero?
The windiest day measured in Gero between 1940 and 2025 was 26 September 1959, with winds reaching 55.0 km/h.
What is the warmest month in Gero?
The warmest month in Gero is August (22.6 °C on average); the coldest is January (-2.4 °C).
How much does it rain in Gero?
Gero receives on average 2,358 mm of precipitation per year, spread over about 183 rainy days.
Is it sunny in Gero?
Gero gets on average 8.4 hours of sunshine per day, roughly 3,066 hours per year over 1940-2025.
What is the biggest single-day snowfall in Gero?
The heaviest 24-hour snowfall measured in Gero between 1940 and 2025 was 15 February 2014, with 27.0 cm.
Are there tropical nights in Gero?
Yes: Gero has on average 19 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Gero?
In Gero, between 1940 and 2025, the highest apparent temperature reached 39.3 °C on 30 July 2025, and the lowest was -27.2 °C on 22 January 1942.
Compare Gero with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Gero