Yanai climate — normals and trends
Yanai (Japan) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 16.0 °C and it receives 1,617 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 (26.6 °C on average) and the coldest is January (6.1 °C). Rainfall peaks in June.
Yanai averages 2 frost days, 8 hot days (≥ 30 °C) and 128 rainy days per year.
Yanai 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 4 to 0 per year over the period.
The hottest day of the period reached 33.3 °C (on 16 August 1983) and the coldest -5.0 °C (on 16 February 1977).
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
YanaiYamaguchi
- coords
- 33.97°, 132.12°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
16.0°C
Average daily high
18.2°C
Average daily low
13.9°C
Annual rainfall
1,617mm
Sunshine / day
8.8h
Mean relative humidity
75%
Average peak wind
20.1km/h
Seasonal range
20.5°C
Frost days (< 0 °C)
2 d/yr
Hot days (≥ 30 °C)
8 d/yr
Rainy days (≥ 1 mm)
128 d/yr
Annual snowfall
5.3 cm
Average feels-like high
18.0 °C
Average feels-like low
12.6 °C
Average peak gust
36.4 km/h
Tropical nights (≥ 20 °C)
102 d/yr
Solar radiation
14.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.8 °C
since 1940
+0.2 °C per decade · r² = 0.62 · 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
33.3 °C
16 August 1983
Coldest day
-5.0 °C
16 February 1977
Wettest day
190 mm
6 September 2005
Windiest day
88.7 km/h
7 September 2004
Strongest gust
191.9 km/h
7 September 2004
Hottest feels-like
41.1 °C
4 August 2024
Coldest feels-like
-13.2 °C
16 February 1977
Snowiest day
14.3 cm
15 February 1968
Sunniest day
13.9 h
1 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 | 8.9 °C | +0.5 °C | 29 mm | -28 mm |
| Feb | 7.3 °C | -1.6 °C | 60 mm | -17 mm |
| Mar | 12.4 °C | +0.6 °C | 163 mm | +48 mm |
| Apr | 16.4 °C | +0.3 °C | 103 mm | -50 mm |
| May | 19.9 °C | 0.0 °C | 271 mm | +102 mm |
| Jun | 24.5 °C | +1.5 °C | 343 mm | +92 mm |
| Jul | 29.5 °C | +2.6 °C | 85 mm | -133 mm |
| Aug | 30.0 °C | +1.5 °C | 194 mm | +48 mm |
| Sep | 28.0 °C | +2.2 °C | 342 mm | +156 mm |
| Oct | 23.2 °C | +2.0 °C | 93 mm | -16 mm |
| Nov | 17.2 °C | +0.9 °C | 35 mm | -43 mm |
| Dec | 12.4 °C | +1.3 °C | 50 mm | -8 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 Yanai?
Yanai has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 16.0 °C and it receives 1,617 mm of precipitation per year.
What is the hottest day ever recorded in Yanai?
The hottest day measured in Yanai between 1940 and 2025 was 16 August 1983, reaching 33.3 °C.
What is the coldest day in Yanai?
The coldest day measured in Yanai between 1940 and 2025 was 16 February 1977, at -5.0 °C.
Does it snow in Yanai?
Yes. Yanai gets on average 5.3 cm of snow per year and has around 2 frost days.
Has the climate of Yanai warmed?
Yes: Yanai warmed by +1.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Yanai?
The wettest day measured in Yanai between 1940 and 2025 was 6 September 2005, with 190 mm of rain in 24 hours.
What was the windiest day in Yanai?
The windiest day measured in Yanai between 1940 and 2025 was 7 September 2004, with winds reaching 88.7 km/h.
What is the warmest month in Yanai?
The warmest month in Yanai is August (26.6 °C on average); the coldest is January (6.1 °C).
How much does it rain in Yanai?
Yanai receives on average 1,617 mm of precipitation per year, spread over about 128 rainy days.
Is it sunny in Yanai?
Yanai gets on average 8.8 hours of sunshine per day, roughly 3,212 hours per year over 1940-2025.
What is the biggest single-day snowfall in Yanai?
The heaviest 24-hour snowfall measured in Yanai between 1940 and 2025 was 15 February 1968, with 14.3 cm.
Are there tropical nights in Yanai?
Yes: Yanai has on average 102 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Yanai?
In Yanai, between 1940 and 2025, the highest apparent temperature reached 41.1 °C on 4 August 2024, and the lowest was -13.2 °C on 16 February 1977.
Compare Yanai with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Yanai