Oga climate — normals and trends
Oga (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 12.2 °C and it receives 1,889 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 (24.5 °C on average) and the coldest is February (2.0 °C). Rainfall peaks in December.
Oga averages 29 frost days, 0 hot days (≥ 30 °C) and 209 rainy days per year.
Oga has warmed by +1.4 °C between 1940 and 2025, or +0.16 °C per decade. This trend is statistically significant.
The number of frost days there went from about 38 to 20 per year over the period.
The hottest day of the period reached 32.0 °C (on 3 August 1978) and the coldest -6.2 °C (on 2 February 1996).
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
OgaAkita
- coords
- 39.87°, 139.85°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
12.2°C
Average daily high
13.6°C
Average daily low
10.9°C
Annual rainfall
1,889mm
Sunshine / day
8.4h
Mean relative humidity
76%
Average peak wind
32.7km/h
Seasonal range
22.5°C
Frost days (< 0 °C)
29 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
209 d/yr
Annual snowfall
193.2 cm
Average feels-like high
11.4 °C
Average feels-like low
6.9 °C
Average peak gust
46.5 km/h
Tropical nights (≥ 20 °C)
71 d/yr
Solar radiation
14.0 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.4 °C
since 1940
+0.2 °C per decade · r² = 0.36 · 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
32.0 °C
3 August 1978
Coldest day
-6.2 °C
2 February 1996
Wettest day
131 mm
16 September 2013
Windiest day
107.2 km/h
28 September 1991
Strongest gust
160.6 km/h
28 September 1991
Hottest feels-like
39.2 °C
23 August 2023
Coldest feels-like
-17.7 °C
14 January 1967
Snowiest day
19.7 cm
17 January 1960
Sunniest day
14.4 h
21 June 1958
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 | 5.7 °C | +2.0 °C | 213 mm | +32 mm |
| Feb | 4.6 °C | +1.1 °C | 181 mm | +48 mm |
| Mar | 7.6 °C | +1.7 °C | 142 mm | +23 mm |
| Apr | 11.1 °C | +1.2 °C | 193 mm | +83 mm |
| May | 15.3 °C | +1.1 °C | 143 mm | +31 mm |
| Jun | 20.7 °C | +1.8 °C | 121 mm | -0 mm |
| Jul | 26.8 °C | +3.8 °C | 35 mm | -164 mm |
| Aug | 27.7 °C | +2.1 °C | 295 mm | +115 mm |
| Sep | 25.4 °C | +2.6 °C | 327 mm | +132 mm |
| Oct | 18.5 °C | +1.1 °C | 122 mm | -37 mm |
| Nov | 13.4 °C | +1.7 °C | 286 mm | +115 mm |
| Dec | 8.7 °C | +2.1 °C | 337 mm | +128 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 Oga?
Oga has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 12.2 °C and it receives 1,889 mm of precipitation per year.
What is the hottest day ever recorded in Oga?
The hottest day measured in Oga between 1940 and 2025 was 3 August 1978, reaching 32.0 °C.
What is the coldest day in Oga?
The coldest day measured in Oga between 1940 and 2025 was 2 February 1996, at -6.2 °C.
Does it snow in Oga?
Yes. Oga gets on average 193.2 cm of snow per year and has around 29 frost days.
Has the climate of Oga warmed?
Yes: Oga warmed by +1.4 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Oga?
The wettest day measured in Oga between 1940 and 2025 was 16 September 2013, with 131 mm of rain in 24 hours.
What was the windiest day in Oga?
The windiest day measured in Oga between 1940 and 2025 was 28 September 1991, with winds reaching 107.2 km/h.
What is the warmest month in Oga?
The warmest month in Oga is August (24.5 °C on average); the coldest is February (2.0 °C).
How much does it rain in Oga?
Oga receives on average 1,889 mm of precipitation per year, spread over about 209 rainy days.
Is it sunny in Oga?
Oga 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 Oga?
The heaviest 24-hour snowfall measured in Oga between 1940 and 2025 was 17 January 1960, with 19.7 cm.
Are there tropical nights in Oga?
Yes: Oga has on average 71 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Oga?
In Oga, between 1940 and 2025, the highest apparent temperature reached 39.2 °C on 23 August 2023, and the lowest was -17.7 °C on 14 January 1967.
Compare Oga with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Oga