Weather without surprises: Les Ulis keeps close to the norm for mainland French towns
January nights average 1.5°C, July afternoons 25.2°C, and a year brings 735 mm of rain. December is the wettest month, April the driest. By warm days alone, it ranks cooler than 68% of mainland French towns. Waterproofs come out on about 119 days a year, each with 1 mm of rain or more.
Figures from Météo-France’s Gometz-le-Chat. station, 2.7 km west.
A year in Les Ulis at a glance
Each month’s typical high and low in °C, at the Gometz-le-Chat. station.
What a year in Les Ulis feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Gometz-le-Chat..
About 735 mm of rain a year
December is the wettest month and April the driest. About 20 days a year bring 10 mm or more. The wettest of 96 towns of 2,500+ in Essonne.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Trappes
46 frosts and 50 days of 25°C a year
On about 46 nights a year the air drops to 0°C or below, and on about 5 days it stays below freezing all day. About 50 days a year reach 25°C, and 12 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Gometz-le-Chat.: 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 Gometz-le-Chat.
Gometz-le-Chat. is 2.7 km west of Les Ulis. Every figure on this page is the station’s, not a measurement in Les Ulis itself.
| Station (Météo-France number) | Gometz-le-Chat. (91275001) |
| Distance from the town | 2.7 km west |
| Station altitude | 159 m |
| Town altitude (its center) | 160 m |
| Period | 1991–2020 |
| Sunshine measured at | Trappes, 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 Les Ulis 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. 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 |
|---|---|---|---|---|
| Les Ulis | Gometz-le-Chat. | 25.2°C | 1.5°C | 735 mm |
| Bures-sur-Yvette 1.4 km | same station | 25.2°C about the same | 1.5°C about the same | 735 mm |
| Orsay 2 km | Fontenay-lès-B. | 26.1°C 0.9°C warmer | 1.5°C about the same | 696 mm |
| Gometz-le-Châtel 2 km | same station | 25.2°C about the same | 1.5°C about the same | 735 mm |
| Gif-sur-Yvette 3.7 km | same station | 25.2°C about the same | 1.5°C about the same | 735 mm |
| Villejust 4.5 km | same station | 25.2°C about the same | 1.5°C about the same | 735 mm |
| Villebon-sur-Yvette 4.8 km | Brétigny | 26.0°C 0.8°C warmer | 1.7°C about the same | 629 mm |
Les Ulis weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Gometz-le-Chat. station; sunshine at Trappes.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 6.7°C | 1.5°C | 4.1°C | 60 mm | 57 |
| February | 7.9°C | 1.3°C | 4.6°C | 54 mm | 81 |
| March | 11.9°C | 3.4°C | 7.7°C | 54 mm | 134 |
| April | 15.6°C | 5.3°C | 10.5°C | 52 mm | 176 |
| May | 19.2°C | 8.6°C | 13.9°C | 73 mm | 202 |
| June | 22.6°C | 11.6°C | 17.1°C | 61 mm | 210 |
| July | 25.2°C | 13.4°C | 19.3°C | 61 mm | 222 |
| August | 25.2°C | 13.2°C | 19.2°C | 60 mm | 216 |
| September | 21.1°C | 10.4°C | 15.8°C | 53 mm | 177 |
| October | 15.9°C | 7.9°C | 11.9°C | 65 mm | 117 |
| November | 10.3°C | 4.4°C | 7.4°C | 67 mm | 68 |
| December | 7.1°C | 2.0°C | 4.5°C | 77 mm | 55 |
| Year | 15.7°C | 6.9°C | 11.3°C | 735 mm | 1,714 |
Where Les Ulis’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Gometz-le-Chat., 2.7 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, Trappes, 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 Essonne.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Les Ulis’s climate
How warm does Les Ulis get in summer?
July is the warmest month, with average highs of 25.2°C. About 50 days a year reach 25°C, fewer than 68% of mainland French towns, and about 12 reach 30°C.
How cold does Les Ulis get in winter?
February nights average 1.3°C. The air drops to 0°C or below on about 46 nights a year, and about 5 days a year stay below freezing all day.
How much rain does Les Ulis get?
About 735 mm a year, less than 58% of mainland French towns. December is the wettest month (77 mm) and April the driest (52 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Trappes (16 km away), averages 1,714 hours of sunshine a year.
Are these figures for Les Ulis itself?
No: they are the normals of the Météo-France station matched to Les Ulis, Gometz-le-Chat., 2.7 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 GOMETZ-LE-CHAT., edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Les Ulis →
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.