Bonan climate — normals and trends
Bonan (China) has a subtropical highland, dry winter climate (Cwb) under the Köppen-Geiger classification. Its mean annual temperature is 14.4 °C and it receives 1,398 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 June (19.4 °C on average) and the coldest is January (7.4 °C). Rainfall peaks in July.
Bonan averages 20 frost days, 1 hot days (≥ 30 °C) and 186 rainy days per year.
Bonan has warmed by +2.4 °C between 1940 and 2025, or +0.28 °C per decade. This trend is statistically significant.
The number of frost days there went from about 30 to 10 per year over the period.
The hottest day of the period reached 32.6 °C (on 31 May 2023) and the coldest -8.1 °C (on 1 January 1984).
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
BonanYunnan
- coords
- 25.46°, 99.53°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
14.4°C
Average daily high
20.0°C
Average daily low
9.7°C
Annual rainfall
1,398mm
Sunshine / day
9.0h
Mean relative humidity
75%
Average peak wind
8.9km/h
Seasonal range
12.0°C
Frost days (< 0 °C)
20 d/yr
Hot days (≥ 30 °C)
1 d/yr
Rainy days (≥ 1 mm)
186 d/yr
Annual snowfall
2.0 cm
Average feels-like high
19.7 °C
Average feels-like low
9.0 °C
Average peak gust
35.4 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
15.9 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.4 °C
since 1940
+0.3 °C per decade · r² = 0.74 · 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
32.6 °C
31 May 2023
Coldest day
-8.1 °C
1 January 1984
Wettest day
100 mm
9 June 1978
Windiest day
22.4 km/h
4 March 1946
Strongest gust
78.8 km/h
13 January 1957
Hottest feels-like
33.6 °C
19 August 2016
Coldest feels-like
-12.3 °C
1 January 1984
Snowiest day
13.0 cm
28 December 1983
Sunniest day
13.0 h
5 June 2023
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 | 15.3 °C | +0.9 °C | 27 mm | +2 mm |
| Feb | 16.8 °C | +0.7 °C | 16 mm | -18 mm |
| Mar | 19.1 °C | 0.0 °C | 60 mm | +16 mm |
| Apr | 22.9 °C | +1.3 °C | 50 mm | -1 mm |
| May | 22.3 °C | -1.2 °C | 217 mm | +108 mm |
| Jun | 24.3 °C | +0.9 °C | 286 mm | +62 mm |
| Jul | 25.2 °C | +2.4 °C | 295 mm | +20 mm |
| Aug | 23.9 °C | +0.5 °C | 233 mm | -12 mm |
| Sep | 24.2 °C | +1.5 °C | 270 mm | +81 mm |
| Oct | 22.2 °C | +1.6 °C | 157 mm | +22 mm |
| Nov | 18.2 °C | +0.7 °C | 58 mm | +13 mm |
| Dec | 16.7 °C | +1.8 °C | 0 mm | -22 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 Bonan?
Bonan has a subtropical highland, dry winter climate (Köppen Cwb). Over 1940-2025, the average annual temperature is 14.4 °C and it receives 1,398 mm of precipitation per year.
What is the hottest day ever recorded in Bonan?
The hottest day measured in Bonan between 1940 and 2025 was 31 May 2023, reaching 32.6 °C.
What is the coldest day in Bonan?
The coldest day measured in Bonan between 1940 and 2025 was 1 January 1984, at -8.1 °C.
Does it snow in Bonan?
Yes. Bonan gets on average 2.0 cm of snow per year and has around 20 frost days.
Has the climate of Bonan warmed?
Yes: Bonan warmed by +2.4 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Bonan?
The wettest day measured in Bonan between 1940 and 2025 was 9 June 1978, with 100 mm of rain in 24 hours.
What was the windiest day in Bonan?
The windiest day measured in Bonan between 1940 and 2025 was 4 March 1946, with winds reaching 22.4 km/h.
What is the warmest month in Bonan?
The warmest month in Bonan is June (19.4 °C on average); the coldest is January (7.4 °C).
How much does it rain in Bonan?
Bonan receives on average 1,398 mm of precipitation per year, spread over about 186 rainy days.
Is it sunny in Bonan?
Bonan gets on average 9.0 hours of sunshine per day, roughly 3,285 hours per year over 1940-2025.
What is the biggest single-day snowfall in Bonan?
The heaviest 24-hour snowfall measured in Bonan between 1940 and 2025 was 28 December 1983, with 13.0 cm.
Are there tropical nights in Bonan?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Bonan.
What was the most extreme apparent temperature in Bonan?
In Bonan, between 1940 and 2025, the highest apparent temperature reached 33.6 °C on 19 August 2016, and the lowest was -12.3 °C on 1 January 1984.
Compare Bonan with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Bonan