Chongming climate — normals and trends
Chongming (China) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 16.3 °C and it receives 1,341 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 (27.5 °C on average) and the coldest is January (5.0 °C). Rainfall peaks in June.
Chongming averages 7 frost days, 16 hot days (≥ 30 °C) and 122 rainy days per year.
Chongming has warmed by +1.5 °C between 1940 and 2025, or +0.18 °C per decade. This trend is statistically significant.
The number of frost days there went from about 10 to 4 per year over the period.
The hottest day of the period reached 34.6 °C (on 8 August 2013) and the coldest -7.8 °C (on 16 January 1958).
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
Chongming
- coords
- 31.62°, 121.70°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
16.3°C
Average daily high
17.7°C
Average daily low
15.0°C
Annual rainfall
1,341mm
Sunshine / day
8.0h
Mean relative humidity
80%
Average peak wind
23.8km/h
Seasonal range
22.5°C
Frost days (< 0 °C)
7 d/yr
Hot days (≥ 30 °C)
16 d/yr
Rainy days (≥ 1 mm)
122 d/yr
Annual snowfall
3.4 cm
Average feels-like high
17.7 °C
Average feels-like low
13.5 °C
Average peak gust
36.0 km/h
Tropical nights (≥ 20 °C)
128 d/yr
Solar radiation
14.4 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.5 °C
since 1940
+0.2 °C per decade · r² = 0.39 · 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
34.6 °C
8 August 2013
Coldest day
-7.8 °C
16 January 1958
Wettest day
176 mm
10 June 1960
Windiest day
79.9 km/h
21 August 1951
Strongest gust
125.3 km/h
27 July 1960
Hottest feels-like
43.7 °C
7 August 2013
Coldest feels-like
-17.3 °C
24 January 2016
Snowiest day
11.8 cm
17 February 1964
Sunniest day
14.0 h
3 July 1940
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 | 8.3 °C | +1.8 °C | 18 mm | -33 mm |
| Feb | 7.1 °C | +0.2 °C | 29 mm | -40 mm |
| Mar | 12.7 °C | +2.4 °C | 100 mm | -3 mm |
| Apr | 18.4 °C | +3.0 °C | 50 mm | -70 mm |
| May | 22.1 °C | +1.7 °C | 179 mm | +36 mm |
| Jun | 26.1 °C | +1.9 °C | 330 mm | +82 mm |
| Jul | 29.9 °C | +1.4 °C | 217 mm | +52 mm |
| Aug | 31.4 °C | +2.7 °C | 52 mm | -80 mm |
| Sep | 29.4 °C | +3.9 °C | 106 mm | -32 mm |
| Oct | 23.7 °C | +3.0 °C | 67 mm | -1 mm |
| Nov | 16.1 °C | +0.6 °C | 8 mm | -52 mm |
| Dec | 11.6 °C | +2.0 °C | 4 mm | -40 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 Chongming?
Chongming has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 16.3 °C and it receives 1,341 mm of precipitation per year.
What is the hottest day ever recorded in Chongming?
The hottest day measured in Chongming between 1940 and 2025 was 8 August 2013, reaching 34.6 °C.
What is the coldest day in Chongming?
The coldest day measured in Chongming between 1940 and 2025 was 16 January 1958, at -7.8 °C.
Does it snow in Chongming?
Yes. Chongming gets on average 3.4 cm of snow per year and has around 7 frost days.
Has the climate of Chongming warmed?
Yes: Chongming warmed by +1.5 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Chongming?
The wettest day measured in Chongming between 1940 and 2025 was 10 June 1960, with 176 mm of rain in 24 hours.
What was the windiest day in Chongming?
The windiest day measured in Chongming between 1940 and 2025 was 21 August 1951, with winds reaching 79.9 km/h.
What is the warmest month in Chongming?
The warmest month in Chongming is August (27.5 °C on average); the coldest is January (5.0 °C).
How much does it rain in Chongming?
Chongming receives on average 1,341 mm of precipitation per year, spread over about 122 rainy days.
Is it sunny in Chongming?
Chongming gets on average 8.0 hours of sunshine per day, roughly 2,920 hours per year over 1940-2025.
What is the biggest single-day snowfall in Chongming?
The heaviest 24-hour snowfall measured in Chongming between 1940 and 2025 was 17 February 1964, with 11.8 cm.
Are there tropical nights in Chongming?
Yes: Chongming has on average 128 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Chongming?
In Chongming, between 1940 and 2025, the highest apparent temperature reached 43.7 °C on 7 August 2013, and the lowest was -17.3 °C on 24 January 2016.
Compare Chongming with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Chongming