Longtan climate — normals and trends
Longtan (China) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 15.6 °C and it receives 1,972 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 July (26.0 °C on average) and the coldest is January (4.1 °C). Rainfall peaks in June.
Longtan averages 21 frost days, 43 hot days (≥ 30 °C) and 200 rainy days per year.
Longtan 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 32 to 10 per year over the period.
The hottest day of the period reached 38.5 °C (on 20 August 2022) and the coldest -15.4 °C (on 20 December 1947).
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
LongtanChongqing Municipality
- coords
- 28.76°, 108.96°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
15.6°C
Average daily high
18.9°C
Average daily low
12.6°C
Annual rainfall
1,972mm
Sunshine / day
5.6h
Mean relative humidity
80%
Average peak wind
8.4km/h
Seasonal range
21.9°C
Frost days (< 0 °C)
21 d/yr
Hot days (≥ 30 °C)
43 d/yr
Rainy days (≥ 1 mm)
200 d/yr
Annual snowfall
39.6 cm
Average feels-like high
19.7 °C
Average feels-like low
12.8 °C
Average peak gust
23.6 km/h
Tropical nights (≥ 20 °C)
92 d/yr
Solar radiation
10.9 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.5 °C
since 1940
+0.2 °C per decade · r² = 0.48 · 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
38.5 °C
20 August 2022
Coldest day
-15.4 °C
20 December 1947
Wettest day
167 mm
28 July 1982
Windiest day
32.2 km/h
5 June 1946
Strongest gust
81.4 km/h
5 July 1946
Hottest feels-like
43.9 °C
27 July 1971
Coldest feels-like
-19.8 °C
20 December 1947
Snowiest day
14.7 cm
4 January 1970
Sunniest day
13.6 h
10 July 1944
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 | 10.5 °C | +3.7 °C | 67 mm | -13 mm |
| Feb | 8.6 °C | +0.2 °C | 85 mm | -13 mm |
| Mar | 15.4 °C | +1.9 °C | 96 mm | -62 mm |
| Apr | 23.5 °C | +4.0 °C | 150 mm | -64 mm |
| May | 25.5 °C | +1.9 °C | 242 mm | -25 mm |
| Jun | 27.4 °C | +0.6 °C | 292 mm | +18 mm |
| Jul | 32.4 °C | +2.6 °C | 123 mm | -113 mm |
| Aug | 31.7 °C | +2.0 °C | 143 mm | -32 mm |
| Sep | 26.8 °C | +1.2 °C | 202 mm | +56 mm |
| Oct | 21.2 °C | +1.5 °C | 150 mm | +3 mm |
| Nov | 16.3 °C | +1.8 °C | 84 mm | -22 mm |
| Dec | 12.1 °C | +3.0 °C | 68 mm | -2 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 Longtan?
Longtan has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 15.6 °C and it receives 1,972 mm of precipitation per year.
What is the hottest day ever recorded in Longtan?
The hottest day measured in Longtan between 1940 and 2025 was 20 August 2022, reaching 38.5 °C.
What is the coldest day in Longtan?
The coldest day measured in Longtan between 1940 and 2025 was 20 December 1947, at -15.4 °C.
Does it snow in Longtan?
Yes. Longtan gets on average 39.6 cm of snow per year and has around 21 frost days.
Has the climate of Longtan warmed?
Yes: Longtan warmed by +1.5 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Longtan?
The wettest day measured in Longtan between 1940 and 2025 was 28 July 1982, with 167 mm of rain in 24 hours.
What was the windiest day in Longtan?
The windiest day measured in Longtan between 1940 and 2025 was 5 June 1946, with winds reaching 32.2 km/h.
What is the warmest month in Longtan?
The warmest month in Longtan is July (26.0 °C on average); the coldest is January (4.1 °C).
How much does it rain in Longtan?
Longtan receives on average 1,972 mm of precipitation per year, spread over about 200 rainy days.
Is it sunny in Longtan?
Longtan gets on average 5.6 hours of sunshine per day, roughly 2,044 hours per year over 1940-2025.
What is the biggest single-day snowfall in Longtan?
The heaviest 24-hour snowfall measured in Longtan between 1940 and 2025 was 4 January 1970, with 14.7 cm.
Are there tropical nights in Longtan?
Yes: Longtan has on average 92 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Longtan?
In Longtan, between 1940 and 2025, the highest apparent temperature reached 43.9 °C on 27 July 1971, and the lowest was -19.8 °C on 20 December 1947.
Compare Longtan with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Longtan