Summer warmth: Fosses logs fewer 25-degree days than 72% of mainland French towns
January mornings start at about 2.3°C. From frosty January to warm July, readings climb 23°C. None of the 76 towns of 2,500+ in Val-d'Oise gets more rain. Frost greets about 33 mornings a year, so leave time to clear the car.
These are the figures of Météo-France’s Roissy station, 9.5 km south.
A year in Fosses at a glance
Each month’s typical high and low in °C, at the Roissy station.
What a year in Fosses feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Roissy.
About 694 mm of rain a year
December is the wettest month and April the driest. About 19 days a year bring 10 mm or more. The wettest of 76 towns of 2,500+ in Val-d'Oise.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Le Bourget
33 frosts and 47 days of 25°C a year
On about 33 nights a year the air drops to 0°C or below, and on about 5 days it stays below freezing all day. About 47 days a year reach 25°C, and 11 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Roissy: a frost is a night of 0°C or below, a summer day (jour d’été) 25°C or more, a hot day (forte chaleur) 30°C or more.
The Météo-France station at Roissy
Roissy is 9.5 km south of Fosses. Every figure on this page is the station’s, not a measurement in Fosses itself.
| Station (Météo-France number) | Roissy (95527001) |
| Distance from the town | 9.5 km south |
| Station altitude | 108 m |
| Town altitude (its center) | 119 m |
| Period | 1991–2020 |
| Nearest station of any kind | 3.4 km |
| Sunshine measured at | Le Bourget, 16 km away |
TownRatings matches each commune to one station with at least 24 years of temperature and rain records: the nearest, counting every 100 m of height difference as 10 km, never across the sea.
How Fosses compares
Against the 4,385 towns of 2,500 or more in mainland France, each read from its own matched station. The dots are the other towns of 2,500+ in Val-d'Oise.
Nearby towns’ climate
The nearest towns of 2,500+ within 29 km. Where a neighbor uses the same station its figures are the same: the differences you’d feel over a few kilometers aren’t in the normals.
| Town | Station | July high | January low | Rain a year |
|---|---|---|---|---|
| Fosses | Roissy | 25.1°C | 2.3°C | 694 mm |
| Marly-la-Ville 1.3 km | same station | 25.1°C about the same | 2.3°C about the same | 694 mm |
| Survilliers 2.4 km | same station | 25.1°C about the same | 2.3°C about the same | 694 mm |
| La Chapelle-en-Serval 3.2 km | same station | 25.1°C about the same | 2.3°C about the same | 694 mm |
| Orry-la-Ville 3.7 km | Creil | 24.9°C about the same | 1.4°C 0.9°C colder | 662 mm |
| Puiseux-en-France 4.4 km | same station | 25.1°C about the same | 2.3°C about the same | 694 mm |
| Saint-Witz 4.4 km | same station | 25.1°C about the same | 2.3°C about the same | 694 mm |
Fosses weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Roissy station; sunshine at Le Bourget.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 7.0°C | 2.3°C | 4.7°C | 57 mm | 57 |
| February | 8.2°C | 2.3°C | 5.3°C | 48 mm | 74 |
| March | 12.2°C | 4.5°C | 8.3°C | 50 mm | 129 |
| April | 15.8°C | 6.7°C | 11.2°C | 48 mm | 171 |
| May | 19.3°C | 10.0°C | 14.6°C | 67 mm | 189 |
| June | 22.6°C | 13.1°C | 17.8°C | 62 mm | 203 |
| July | 25.1°C | 15.1°C | 20.1°C | 60 mm | 213 |
| August | 25.1°C | 15.0°C | 20.1°C | 58 mm | 206 |
| September | 21.1°C | 12.1°C | 16.6°C | 50 mm | 162 |
| October | 16.2°C | 9.2°C | 12.7°C | 60 mm | 111 |
| November | 10.7°C | 5.4°C | 8.1°C | 60 mm | 64 |
| December | 7.5°C | 2.9°C | 5.2°C | 75 mm | 54 |
| Year | 15.9°C | 8.2°C | 12.1°C | 694 mm | 1,634 |
Where Fosses’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Roissy, 9.5 km away: statistics for 1991–2020.
- Which station: among stations with at least 24 of the 30 years of temperature and rain, the nearest to the commune’s population-weighted center, counting each 100 m of height difference as 10 km; mainland towns use mainland stations and each overseas département its own.
- Altitudes: the town’s from IGN’s RGE ALTI® at its population-weighted center; the station’s from Météo-France.
- Sunshine: the nearest station with at least 10 years of sunshine records, Le Bourget, 16 km away.
- Comparisons: every town of 2,500 or more in mainland France, read the same way; the dots are the towns of 2,500+ in Val-d'Oise.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Fosses’s climate
How warm does Fosses get in summer?
July is the warmest month, with average highs of 25.1°C. About 47 days a year reach 25°C, fewer than 72% of mainland French towns, and about 11 reach 30°C.
How cold does Fosses get in winter?
January nights average 2.3°C. The air drops to 0°C or below on about 33 nights a year, and about 5 days a year stay below freezing all day.
How much rain does Fosses get?
About 694 mm a year, less than 70% of mainland French towns. December is the wettest month (75 mm) and April the driest (48 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Le Bourget (16 km away), averages 1,634 hours of sunshine a year.
Are these figures for Fosses itself?
No: they are the normals of the Météo-France station matched to Fosses, Roissy, 9.5 km away. France publishes its climate normals by station, not by commune; a valley, a hill or the sea can make a difference over a few kilometers.
Where do these figures come from?
Météo-France’s fiches climatologiques: 30-year averages (1991–2020) for each of its long-running stations, published as open data since 2024. They are normals, not a forecast.
Source: Météo-France, fiches climatologiques, 1991–2020 statistics (station ROISSY, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Fosses →
Contains public sector information under the Licence Ouverte / Open Licence 2.0 (Etalab): INSEE, DGFiP, the Interior Ministry’s statistics service (SSMSI), the Ministry of Education (DEPP), the Health Ministry’s statistics service (DREES) and the Housing Ministry (Carte des loyers). Commune boundaries: IGN Admin Express.