Chantilly climate — normals and trends
Chantilly (United States) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 13.1 °C and it receives 1,027 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 (25.2 °C on average) and the coldest is January (0.8 °C). Rainfall peaks in May.
Chantilly averages 79 frost days, 52 hot days (≥ 30 °C) and 117 rainy days per year.
Chantilly has warmed by +1.8 °C between 1940 and 2025, or +0.21 °C per decade. This trend is statistically significant.
The number of frost days there went from about 88 to 70 per year over the period.
The hottest day of the period reached 40.0 °C (on 16 July 1988) and the coldest -25.4 °C (on 22 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
ChantillyVirginia
- coords
- 38.89°, -77.43°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
13.1°C
Average daily high
18.2°C
Average daily low
8.5°C
Annual rainfall
1,027mm
Sunshine / day
9.0h
Mean relative humidity
67%
Average peak wind
15.3km/h
Seasonal range
24.4°C
Frost days (< 0 °C)
79 d/yr
Hot days (≥ 30 °C)
52 d/yr
Rainy days (≥ 1 mm)
117 d/yr
Annual snowfall
49.6 cm
Average feels-like high
17.2 °C
Average feels-like low
6.4 °C
Average peak gust
36.5 km/h
Tropical nights (≥ 20 °C)
50 d/yr
Solar radiation
15.1 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.8 °C
since 1940
+0.2 °C per decade · r² = 0.44 · 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
40.0 °C
16 July 1988
Coldest day
-25.4 °C
22 January 1984
Wettest day
150 mm
14 September 1966
Windiest day
45.3 km/h
3 April 1975
Strongest gust
120.6 km/h
19 September 2003
Hottest feels-like
45.5 °C
22 July 2011
Coldest feels-like
-30.4 °C
22 January 1984
Snowiest day
34.7 cm
23 January 2016
Sunniest day
14.3 h
2 July 2001
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 | 3.2 °C | -1.8 °C | 53 mm | -24 mm |
| Feb | 7.3 °C | +0.3 °C | 78 mm | +4 mm |
| Mar | 16.6 °C | +4.6 °C | 44 mm | -47 mm |
| Apr | 20.4 °C | +2.1 °C | 78 mm | -8 mm |
| May | 23.4 °C | 0.0 °C | 191 mm | +94 mm |
| Jun | 29.8 °C | +1.5 °C | 141 mm | +55 mm |
| Jul | 31.8 °C | +1.3 °C | 190 mm | +97 mm |
| Aug | 28.0 °C | -1.4 °C | 23 mm | -64 mm |
| Sep | 26.7 °C | +1.1 °C | 76 mm | -16 mm |
| Oct | 19.9 °C | +0.5 °C | 46 mm | -33 mm |
| Nov | 13.7 °C | +0.7 °C | 39 mm | -42 mm |
| Dec | 6.0 °C | -1.1 °C | 48 mm | -35 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 Chantilly?
Chantilly has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 13.1 °C and it receives 1,027 mm of precipitation per year.
What is the hottest day ever recorded in Chantilly?
The hottest day measured in Chantilly between 1940 and 2025 was 16 July 1988, reaching 40.0 °C.
What is the coldest day in Chantilly?
The coldest day measured in Chantilly between 1940 and 2025 was 22 January 1984, at -25.4 °C.
Does it snow in Chantilly?
Yes. Chantilly gets on average 49.6 cm of snow per year and has around 79 frost days.
Has the climate of Chantilly warmed?
Yes: Chantilly warmed by +1.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Chantilly?
The wettest day measured in Chantilly between 1940 and 2025 was 14 September 1966, with 150 mm of rain in 24 hours.
What was the windiest day in Chantilly?
The windiest day measured in Chantilly between 1940 and 2025 was 3 April 1975, with winds reaching 45.3 km/h.
What is the warmest month in Chantilly?
The warmest month in Chantilly is July (25.2 °C on average); the coldest is January (0.8 °C).
How much does it rain in Chantilly?
Chantilly receives on average 1,027 mm of precipitation per year, spread over about 117 rainy days.
Is it sunny in Chantilly?
Chantilly 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 Chantilly?
The heaviest 24-hour snowfall measured in Chantilly between 1940 and 2025 was 23 January 2016, with 34.7 cm.
Are there tropical nights in Chantilly?
Yes: Chantilly has on average 50 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Chantilly?
In Chantilly, between 1940 and 2025, the highest apparent temperature reached 45.5 °C on 22 July 2011, and the lowest was -30.4 °C on 22 January 1984.
Compare Chantilly with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Chantilly