Photo: Spedona · CC BY-SA 3.0Less rain falls on Le Mesnil-le-Roi than on 79% of mainland French towns: 667 mm a year
Peak summer warmth arrives in July, with afternoons near 26.1°C. Rain peaks in December and eases off in April. By frosts alone, it ranks gentler than 67% of mainland French towns. Plan for rain on about 115 days a year, the days with 1 mm or more.
Figures from Météo-France’s Pontoise -Ville station, 13 km north.
A year in Le Mesnil-le-Roi at a glance
Each month’s typical high and low in °C, at the Pontoise -Ville station.
What a year in Le Mesnil-le-Roi feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Pontoise -Ville.
About 667 mm of rain a year
December is the wettest month and April the driest. About 18 days a year bring 10 mm or more. 59th wettest of 95 towns of 2,500+ in Yvelines.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Trappes
35 frosts and 62 days of 25°C a year
On about 35 nights a year the air drops to 0°C or below, and on about 3 days it stays below freezing all day. About 62 days a year reach 25°C, and 18 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Pontoise -Ville: 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 Pontoise -Ville
Pontoise -Ville is 13 km north of Le Mesnil-le-Roi. Every figure on this page is the station’s, not a measurement in Le Mesnil-le-Roi itself.
| Station (Météo-France number) | Pontoise -Ville (95500003) |
| Distance from the town | 13 km north |
| Station altitude | 50 m |
| Town altitude (its center) | 64 m |
| Period | 1991–2020 |
| Nearest station of any kind | 11 km |
| Sunshine measured at | Trappes, 20 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 Le Mesnil-le-Roi 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 Yvelines.
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 |
|---|---|---|---|---|
| Le Mesnil-le-Roi | Pontoise -Ville | 26.1°C | 2.7°C | 667 mm |
| Maisons-Laffitte 2.3 km | Bagatelle | 26.4°C about the same | 2.7°C about the same | 639 mm |
| Montesson 2.8 km | Bagatelle | 26.4°C about the same | 2.7°C about the same | 639 mm |
| Sartrouville 3.8 km | Bagatelle | 26.4°C about the same | 2.7°C about the same | 639 mm |
| Le Vésinet 4.6 km | Bagatelle | 26.4°C about the same | 2.7°C about the same | 639 mm |
| Houilles 4.6 km | Bagatelle | 26.4°C about the same | 2.7°C about the same | 639 mm |
| Chatou 4.7 km | Bagatelle | 26.4°C about the same | 2.7°C about the same | 639 mm |
Le Mesnil-le-Roi weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Pontoise -Ville station; sunshine at Trappes.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 7.8°C | 2.7°C | 5.3°C | 58 mm | 57 |
| February | 9.1°C | 2.6°C | 5.8°C | 52 mm | 81 |
| March | 13.1°C | 4.5°C | 8.8°C | 49 mm | 134 |
| April | 16.9°C | 6.4°C | 11.7°C | 45 mm | 176 |
| May | 20.5°C | 9.8°C | 15.2°C | 62 mm | 202 |
| June | 23.8°C | 13.0°C | 18.4°C | 54 mm | 210 |
| July | 26.1°C | 14.9°C | 20.5°C | 49 mm | 222 |
| August | 26.2°C | 14.7°C | 20.4°C | 53 mm | 216 |
| September | 22.2°C | 11.7°C | 16.9°C | 46 mm | 177 |
| October | 17.0°C | 9.1°C | 13.0°C | 64 mm | 117 |
| November | 11.5°C | 5.6°C | 8.5°C | 59 mm | 68 |
| December | 8.2°C | 3.3°C | 5.7°C | 75 mm | 55 |
| Year | 16.9°C | 8.2°C | 12.5°C | 667 mm | 1,714 |
Where Le Mesnil-le-Roi’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Pontoise -Ville, 13 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, 20 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 Yvelines.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Le Mesnil-le-Roi’s climate
How warm does Le Mesnil-le-Roi get in summer?
August is the warmest month, with average highs of 26.2°C. About 62 days a year reach 25°C, more than 53% of mainland French towns, and about 18 reach 30°C.
How cold does Le Mesnil-le-Roi get in winter?
February nights average 2.6°C. The air drops to 0°C or below on about 35 nights a year, and about 3 days a year stay below freezing all day.
How much rain does Le Mesnil-le-Roi get?
About 667 mm a year, less than 79% of mainland French towns. December is the wettest month (75 mm) and April the driest (45 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Trappes (20 km away), averages 1,714 hours of sunshine a year.
Are these figures for Le Mesnil-le-Roi itself?
No: they are the normals of the Météo-France station matched to Le Mesnil-le-Roi, Pontoise -Ville, 13 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 PONTOISE -VILLE, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Le Mesnil-le-Roi →
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.