Bibai climate — normals and trends
Bibai (Japan) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 7.1 °C and it receives 1,025 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 (21.0 °C on average) and the coldest is January (-7.0 °C). Rainfall peaks in August.
Bibai averages 148 frost days, 1 hot days (≥ 30 °C) and 162 rainy days per year.
Bibai has warmed by +2.5 °C between 1940 and 2025, or +0.30 °C per decade. This trend is statistically significant.
The number of frost days there went from about 163 to 133 per year over the period.
The hottest day of the period reached 33.0 °C (on 7 August 1994) and the coldest -24.6 °C (on 17 February 1978).
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
BibaiHokkaido
- coords
- 43.32°, 141.86°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
7.1°C
Average daily high
10.9°C
Average daily low
3.1°C
Annual rainfall
1,025mm
Sunshine / day
8.4h
Mean relative humidity
77%
Average peak wind
17.0km/h
Seasonal range
28.0°C
Frost days (< 0 °C)
148 d/yr
Hot days (≥ 30 °C)
1 d/yr
Rainy days (≥ 1 mm)
162 d/yr
Annual snowfall
172.0 cm
Average feels-like high
8.8 °C
Average feels-like low
0.4 °C
Average peak gust
36.7 km/h
Tropical nights (≥ 20 °C)
12 d/yr
Solar radiation
13.3 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.5 °C
since 1940
+0.3 °C per decade · r² = 0.65 · 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
33.0 °C
7 August 1994
Coldest day
-24.6 °C
17 February 1978
Wettest day
132 mm
17 August 2016
Windiest day
59.4 km/h
8 September 2004
Strongest gust
130.0 km/h
26 September 1954
Hottest feels-like
39.5 °C
25 July 2025
Coldest feels-like
-29.7 °C
17 February 1978
Snowiest day
34.6 cm
5 February 1969
Sunniest day
15.0 h
23 June 1941
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 | 0.1 °C | +3.5 °C | 60 mm | +9 mm |
| Feb | 0.5 °C | +2.9 °C | 53 mm | +6 mm |
| Mar | 3.9 °C | +1.9 °C | 87 mm | +27 mm |
| Apr | 11.5 °C | +1.4 °C | 127 mm | +52 mm |
| May | 18.6 °C | +2.6 °C | 62 mm | -21 mm |
| Jun | 23.7 °C | +4.3 °C | 96 mm | +24 mm |
| Jul | 28.4 °C | +5.2 °C | 102 mm | +0 mm |
| Aug | 27.2 °C | +2.7 °C | 140 mm | -9 mm |
| Sep | 23.6 °C | +2.9 °C | 216 mm | +88 mm |
| Oct | 14.1 °C | -0.2 °C | 81 mm | -17 mm |
| Nov | 7.5 °C | +1.1 °C | 153 mm | +65 mm |
| Dec | 1.2 °C | +1.6 °C | 118 mm | +48 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 Bibai?
Bibai has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 7.1 °C and it receives 1,025 mm of precipitation per year.
What is the hottest day ever recorded in Bibai?
The hottest day measured in Bibai between 1940 and 2025 was 7 August 1994, reaching 33.0 °C.
What is the coldest day in Bibai?
The coldest day measured in Bibai between 1940 and 2025 was 17 February 1978, at -24.6 °C.
Does it snow in Bibai?
Yes. Bibai gets on average 172.0 cm of snow per year and has around 148 frost days.
Has the climate of Bibai warmed?
Yes: Bibai warmed by +2.5 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Bibai?
The wettest day measured in Bibai between 1940 and 2025 was 17 August 2016, with 132 mm of rain in 24 hours.
What was the windiest day in Bibai?
The windiest day measured in Bibai between 1940 and 2025 was 8 September 2004, with winds reaching 59.4 km/h.
What is the warmest month in Bibai?
The warmest month in Bibai is August (21.0 °C on average); the coldest is January (-7.0 °C).
How much does it rain in Bibai?
Bibai receives on average 1,025 mm of precipitation per year, spread over about 162 rainy days.
Is it sunny in Bibai?
Bibai 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 Bibai?
The heaviest 24-hour snowfall measured in Bibai between 1940 and 2025 was 5 February 1969, with 34.6 cm.
Are there tropical nights in Bibai?
Yes: Bibai has on average 12 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Bibai?
In Bibai, between 1940 and 2025, the highest apparent temperature reached 39.5 °C on 25 July 2025, and the lowest was -29.7 °C on 17 February 1978.
Compare Bibai with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Bibai