Poissy climate — normals and trends
Poissy (France) has a temperate oceanic climate (Cfb) under the Köppen-Geiger classification. Its mean annual temperature is 10.8 °C and it receives 671 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 (18.5 °C on average) and the coldest is January (3.5 °C). Rainfall peaks in May.
Poissy averages 43 frost days, 5 hot days (≥ 30 °C) and 129 rainy days per year.
Poissy has warmed by +1.9 °C between 1940 and 2025, or +0.22 °C per decade. This trend is statistically significant.
The number of frost days there went from about 57 to 29 per year over the period.
The hottest day of the period reached 40.1 °C (on 25 July 2019) and the coldest -17.8 °C (on 29 January 1945).
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
PoissyÎle-de-France Region
- coords
- 48.93°, 2.05°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
10.8°C
Average daily high
14.5°C
Average daily low
7.2°C
Annual rainfall
671mm
Sunshine / day
7.7h
Mean relative humidity
79%
Average peak wind
18.0km/h
Seasonal range
15.0°C
Frost days (< 0 °C)
43 d/yr
Hot days (≥ 30 °C)
5 d/yr
Rainy days (≥ 1 mm)
129 d/yr
Annual snowfall
13.2 cm
Average feels-like high
12.3 °C
Average feels-like low
4.6 °C
Average peak gust
37.0 km/h
Tropical nights (≥ 20 °C)
1 d/yr
Solar radiation
11.4 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.9 °C
since 1940
+0.2 °C per decade · r² = 0.43 · 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
40.1 °C
25 July 2019
Coldest day
-17.8 °C
29 January 1945
Wettest day
49 mm
9 October 2024
Windiest day
53.6 km/h
25 January 1990
Strongest gust
119.5 km/h
25 January 1990
Hottest feels-like
40.6 °C
30 July 2024
Coldest feels-like
-23.0 °C
29 January 1945
Snowiest day
15.8 cm
25 April 1941
Sunniest day
15.9 h
1 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 | 6.7 °C | +0.9 °C | 141 mm | +87 mm |
| Feb | 7.7 °C | +0.5 °C | 44 mm | -6 mm |
| Mar | 13.5 °C | +2.7 °C | 27 mm | -26 mm |
| Apr | 18.6 °C | +4.6 °C | 30 mm | -23 mm |
| May | 20.8 °C | +3.2 °C | 34 mm | -30 mm |
| Jun | 26.2 °C | +5.4 °C | 43 mm | -15 mm |
| Jul | 25.0 °C | +1.9 °C | 98 mm | +45 mm |
| Aug | 25.9 °C | +3.0 °C | 32 mm | -21 mm |
| Sep | 20.2 °C | +0.3 °C | 65 mm | +14 mm |
| Oct | 15.9 °C | +0.7 °C | 63 mm | +3 mm |
| Nov | 11.3 °C | +1.6 °C | 50 mm | -11 mm |
| Dec | 9.1 °C | +2.4 °C | 41 mm | -20 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 Poissy?
Poissy has a temperate oceanic climate (Köppen Cfb). Over 1940-2025, the average annual temperature is 10.8 °C and it receives 671 mm of precipitation per year.
What is the hottest day ever recorded in Poissy?
The hottest day measured in Poissy between 1940 and 2025 was 25 July 2019, reaching 40.1 °C.
What is the coldest day in Poissy?
The coldest day measured in Poissy between 1940 and 2025 was 29 January 1945, at -17.8 °C.
Does it snow in Poissy?
Yes. Poissy gets on average 13.2 cm of snow per year and has around 43 frost days.
Has the climate of Poissy warmed?
Yes: Poissy warmed by +1.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Poissy?
The wettest day measured in Poissy between 1940 and 2025 was 9 October 2024, with 49 mm of rain in 24 hours.
What was the windiest day in Poissy?
The windiest day measured in Poissy between 1940 and 2025 was 25 January 1990, with winds reaching 53.6 km/h.
What is the warmest month in Poissy?
The warmest month in Poissy is July (18.5 °C on average); the coldest is January (3.5 °C).
How much does it rain in Poissy?
Poissy receives on average 671 mm of precipitation per year, spread over about 129 rainy days.
Is it sunny in Poissy?
Poissy gets on average 7.7 hours of sunshine per day, roughly 2,811 hours per year over 1940-2025.
What is the biggest single-day snowfall in Poissy?
The heaviest 24-hour snowfall measured in Poissy between 1940 and 2025 was 25 April 1941, with 15.8 cm.
Are there tropical nights in Poissy?
Yes: Poissy has on average 1 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Poissy?
In Poissy, between 1940 and 2025, the highest apparent temperature reached 40.6 °C on 30 July 2024, and the lowest was -23.0 °C on 29 January 1945.
Compare Poissy with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Poissy