Ōarai climate — normals and trends
Ōarai (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 14.8 °C and it receives 1,497 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 (25.2 °C on average) and the coldest is January (5.1 °C). Rainfall peaks in October.
Ōarai averages 7 frost days, 7 hot days (≥ 30 °C) and 147 rainy days per year.
Ōarai has warmed by +1.8 °C between 1940 and 2025, or +0.21 °C per decade. This trend is statistically significant.
The number of frost days there went from about 15 to 0 per year over the period.
The hottest day of the period reached 34.4 °C (on 9 August 2016) and the coldest -7.0 °C (on 5 February 1952).
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
ŌaraiIbaraki
- coords
- 36.31°, 140.58°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
14.8°C
Average daily high
17.3°C
Average daily low
12.5°C
Annual rainfall
1,497mm
Sunshine / day
8.4h
Mean relative humidity
74%
Average peak wind
20.9km/h
Seasonal range
20.1°C
Frost days (< 0 °C)
7 d/yr
Hot days (≥ 30 °C)
7 d/yr
Rainy days (≥ 1 mm)
147 d/yr
Annual snowfall
10.8 cm
Average feels-like high
16.7 °C
Average feels-like low
10.7 °C
Average peak gust
36.0 km/h
Tropical nights (≥ 20 °C)
79 d/yr
Solar radiation
14.2 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.8 °C
since 1940
+0.2 °C per decade · r² = 0.52 · 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
34.4 °C
9 August 2016
Coldest day
-7.0 °C
5 February 1952
Wettest day
174 mm
26 September 1958
Windiest day
72.7 km/h
1 October 2018
Strongest gust
140.4 km/h
1 October 2018
Hottest feels-like
41.6 °C
2 August 2022
Coldest feels-like
-13.4 °C
5 February 1952
Snowiest day
17.9 cm
8 February 2014
Sunniest day
14.0 h
16 June 2007
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 | 9.7 °C | +1.8 °C | 45 mm | -15 mm |
| Feb | 9.2 °C | +0.9 °C | 11 mm | -60 mm |
| Mar | 13.4 °C | +2.2 °C | 181 mm | +66 mm |
| Apr | 17.4 °C | +1.7 °C | 129 mm | +3 mm |
| May | 20.1 °C | +0.7 °C | 237 mm | +95 mm |
| Jun | 25.2 °C | +3.2 °C | 157 mm | -8 mm |
| Jul | 28.9 °C | +3.3 °C | 75 mm | -78 mm |
| Aug | 30.0 °C | +2.6 °C | 57 mm | -66 mm |
| Sep | 27.6 °C | +3.1 °C | 104 mm | -76 mm |
| Oct | 20.7 °C | +0.9 °C | 141 mm | -50 mm |
| Nov | 15.7 °C | +0.5 °C | 62 mm | -43 mm |
| Dec | 11.6 °C | +1.2 °C | 94 mm | +27 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 Ōarai?
Ōarai has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 14.8 °C and it receives 1,497 mm of precipitation per year.
What is the hottest day ever recorded in Ōarai?
The hottest day measured in Ōarai between 1940 and 2025 was 9 August 2016, reaching 34.4 °C.
What is the coldest day in Ōarai?
The coldest day measured in Ōarai between 1940 and 2025 was 5 February 1952, at -7.0 °C.
Does it snow in Ōarai?
Yes. Ōarai gets on average 10.8 cm of snow per year and has around 7 frost days.
Has the climate of Ōarai warmed?
Yes: Ōarai warmed by +1.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Ōarai?
The wettest day measured in Ōarai between 1940 and 2025 was 26 September 1958, with 174 mm of rain in 24 hours.
What was the windiest day in Ōarai?
The windiest day measured in Ōarai between 1940 and 2025 was 1 October 2018, with winds reaching 72.7 km/h.
What is the warmest month in Ōarai?
The warmest month in Ōarai is August (25.2 °C on average); the coldest is January (5.1 °C).
How much does it rain in Ōarai?
Ōarai receives on average 1,497 mm of precipitation per year, spread over about 147 rainy days.
Is it sunny in Ōarai?
Ōarai 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 Ōarai?
The heaviest 24-hour snowfall measured in Ōarai between 1940 and 2025 was 8 February 2014, with 17.9 cm.
Are there tropical nights in Ōarai?
Yes: Ōarai has on average 79 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Ōarai?
In Ōarai, between 1940 and 2025, the highest apparent temperature reached 41.6 °C on 2 August 2022, and the lowest was -13.4 °C on 5 February 1952.
Compare Ōarai with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Ōarai