Orsay gets more frosts than 72% of mainland French towns
The warmest part of a July day comes in at 26.1°C on average. Rain peaks in December and eases off in April. Its yearly rainfall falls short of 69% of mainland French towns. Radiators earn their keep from November to March, the months that average under 10°C.
Figures from Météo-France’s Fontenay-lès-B. station, 9.5 km south.
A year in Orsay at a glance
Each month’s typical high and low in °C, at the Fontenay-lès-B. station.
What a year in Orsay feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Fontenay-lès-B..
About 696 mm of rain a year
December is the wettest month and April the driest. About 18 days a year bring 10 mm or more. 14th wettest of 96 towns of 2,500+ in Essonne.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Orly
A frosty town: 53 frosts and 60 days of 25°C a year
On about 53 nights a year the air drops to 0°C or below, and on about 4 days it stays below freezing all day. About 60 days a year reach 25°C, and 16 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Fontenay-lès-B.: 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 Fontenay-lès-B.
Fontenay-lès-B. is 9.5 km south of Orsay. Every figure on this page is the station’s, not a measurement in Orsay itself.
| Station (Météo-France number) | Fontenay-lès-B. (91243001) |
| Distance from the town | 9.5 km south |
| Station altitude | 109 m |
| Town altitude (its center) | 95 m |
| Period | 1991–2020 |
| Nearest station of any kind | 4.5 km |
| Sunshine measured at | Orly, 15 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 Orsay 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 Essonne.
Nearby towns’ climate
The nearest towns of 2,500+ within 29 km, each with its own matched station.
| Town | Station | July high | January low | Rain a year |
|---|---|---|---|---|
| Orsay | Fontenay-lès-B. | 26.1°C | 1.5°C | 696 mm |
| Les Ulis 2 km | Gometz-le-Chat. | 25.2°C 0.9°C cooler | 1.5°C about the same | 735 mm |
| Bures-sur-Yvette 2.6 km | Gometz-le-Chat. | 25.2°C 0.9°C cooler | 1.5°C about the same | 735 mm |
| Villebon-sur-Yvette 3 km | Brétigny | 26.0°C about the same | 1.7°C about the same | 629 mm |
| Villejust 3.5 km | Gometz-le-Chat. | 25.2°C 0.9°C cooler | 1.5°C about the same | 735 mm |
| Gometz-le-Châtel 3.9 km | Gometz-le-Chat. | 25.2°C 0.9°C cooler | 1.5°C about the same | 735 mm |
| Palaiseau 4.2 km | Gometz-le-Chat. | 25.2°C 0.9°C cooler | 1.5°C about the same | 735 mm |
Orsay weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Fontenay-lès-B. station; sunshine at Orly.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 7.3°C | 1.5°C | 4.4°C | 54 mm | 53 |
| February | 8.5°C | 1.2°C | 4.9°C | 49 mm | 85 |
| March | 12.6°C | 3.1°C | 7.9°C | 50 mm | 153 |
| April | 16.3°C | 5.0°C | 10.7°C | 48 mm | 203 |
| May | 20.1°C | 8.6°C | 14.3°C | 69 mm | 217 |
| June | 23.5°C | 11.6°C | 17.5°C | 58 mm | 224 |
| July | 26.1°C | 13.4°C | 19.8°C | 61 mm | 247 |
| August | 26.0°C | 13.2°C | 19.6°C | 63 mm | 221 |
| September | 21.8°C | 10.2°C | 16.0°C | 51 mm | 186 |
| October | 16.6°C | 7.7°C | 12.1°C | 61 mm | 117 |
| November | 10.9°C | 4.4°C | 7.6°C | 61 mm | 62 |
| December | 7.6°C | 2.1°C | 4.8°C | 71 mm | 64 |
| Year | 16.4°C | 6.8°C | 11.6°C | 696 mm | 1,831 |
Where Orsay’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Fontenay-lès-B., 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, Orly, 15 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 Essonne.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Orsay’s climate
How warm does Orsay get in summer?
July is the warmest month, with average highs of 26.1°C. About 60 days a year reach 25°C, fewer than 50% of mainland French towns, and about 16 reach 30°C.
How cold does Orsay get in winter?
February nights average 1.2°C. The air drops to 0°C or below on about 53 nights a year, and about 4 days a year stay below freezing all day.
How much rain does Orsay get?
About 696 mm a year, less than 69% of mainland French towns. December is the wettest month (71 mm) and April the driest (48 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Orly (15 km away), averages 1,831 hours of sunshine a year.
Are these figures for Orsay itself?
No: they are the normals of the Météo-France station matched to Orsay, Fontenay-lès-B., 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 FONTENAY-LES-B., edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Orsay →
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.