Ryōtsu-minato climate — normals and trends
Ryōtsu-minato (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 13.7 °C and it receives 1,602 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 (26.0 °C on average) and the coldest is January (3.3 °C). Rainfall peaks in July.
Ryōtsu-minato averages 17 frost days, 11 hot days (≥ 30 °C) and 193 rainy days per year.
Ryōtsu-minato 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 32 to 2 per year over the period.
The hottest day of the period reached 36.3 °C (on 10 August 2023) and the coldest -6.9 °C (on 9 February 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
Ryōtsu-minatoNiigata
- coords
- 38.08°, 138.44°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
13.7°C
Average daily high
15.8°C
Average daily low
11.7°C
Annual rainfall
1,602mm
Sunshine / day
8.7h
Mean relative humidity
74%
Average peak wind
21.4km/h
Seasonal range
22.7°C
Frost days (< 0 °C)
17 d/yr
Hot days (≥ 30 °C)
11 d/yr
Rainy days (≥ 1 mm)
193 d/yr
Annual snowfall
78.6 cm
Average feels-like high
14.9 °C
Average feels-like low
9.6 °C
Average peak gust
43.6 km/h
Tropical nights (≥ 20 °C)
78 d/yr
Solar radiation
14.3 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.9 °C
since 1940
+0.2 °C per decade · r² = 0.58 · 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
36.3 °C
10 August 2023
Coldest day
-6.9 °C
9 February 1942
Wettest day
139 mm
25 July 1958
Windiest day
81.2 km/h
28 September 1991
Strongest gust
175.7 km/h
28 September 1991
Hottest feels-like
41.8 °C
22 August 2023
Coldest feels-like
-13.7 °C
25 January 2023
Snowiest day
20.0 cm
12 March 1969
Sunniest day
14.0 h
18 June 2025
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 | 6.1 °C | +1.2 °C | 178 mm | +44 mm |
| Feb | 5.1 °C | +0.1 °C | 100 mm | +3 mm |
| Mar | 9.5 °C | +1.5 °C | 76 mm | -23 mm |
| Apr | 13.5 °C | +0.4 °C | 94 mm | +1 mm |
| May | 18.2 °C | +0.3 °C | 129 mm | +34 mm |
| Jun | 23.7 °C | +1.7 °C | 107 mm | -19 mm |
| Jul | 30.2 °C | +4.2 °C | 21 mm | -182 mm |
| Aug | 29.7 °C | +1.5 °C | 291 mm | +140 mm |
| Sep | 27.0 °C | +2.7 °C | 260 mm | +90 mm |
| Oct | 19.8 °C | +1.0 °C | 187 mm | +57 mm |
| Nov | 13.9 °C | +0.6 °C | 143 mm | +5 mm |
| Dec | 9.5 °C | +1.5 °C | 175 mm | +9 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 Ryōtsu-minato?
Ryōtsu-minato has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 13.7 °C and it receives 1,602 mm of precipitation per year.
What is the hottest day ever recorded in Ryōtsu-minato?
The hottest day measured in Ryōtsu-minato between 1940 and 2025 was 10 August 2023, reaching 36.3 °C.
What is the coldest day in Ryōtsu-minato?
The coldest day measured in Ryōtsu-minato between 1940 and 2025 was 9 February 1942, at -6.9 °C.
Does it snow in Ryōtsu-minato?
Yes. Ryōtsu-minato gets on average 78.6 cm of snow per year and has around 17 frost days.
Has the climate of Ryōtsu-minato warmed?
Yes: Ryōtsu-minato warmed by +1.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Ryōtsu-minato?
The wettest day measured in Ryōtsu-minato between 1940 and 2025 was 25 July 1958, with 139 mm of rain in 24 hours.
What was the windiest day in Ryōtsu-minato?
The windiest day measured in Ryōtsu-minato between 1940 and 2025 was 28 September 1991, with winds reaching 81.2 km/h.
What is the warmest month in Ryōtsu-minato?
The warmest month in Ryōtsu-minato is August (26.0 °C on average); the coldest is January (3.3 °C).
How much does it rain in Ryōtsu-minato?
Ryōtsu-minato receives on average 1,602 mm of precipitation per year, spread over about 193 rainy days.
Is it sunny in Ryōtsu-minato?
Ryōtsu-minato gets on average 8.7 hours of sunshine per day, roughly 3,175 hours per year over 1940-2025.
What is the biggest single-day snowfall in Ryōtsu-minato?
The heaviest 24-hour snowfall measured in Ryōtsu-minato between 1940 and 2025 was 12 March 1969, with 20.0 cm.
Are there tropical nights in Ryōtsu-minato?
Yes: Ryōtsu-minato has on average 78 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Ryōtsu-minato?
In Ryōtsu-minato, between 1940 and 2025, the highest apparent temperature reached 41.8 °C on 22 August 2023, and the lowest was -13.7 °C on 25 January 2023.
Compare Ryōtsu-minato with another city
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Nearby cities
The climate around Ryōtsu-minato