Less rain falls on Saint-Germain-en-Laye than on 85% of mainland French towns: 639 mm a year
The coldest hours of a January night bottom out at 2.7°C on average. Seasons differ by 24°C, from the coldest nights to the warmest afternoons. Of the 95 towns of 2,500+ in Yvelines, it has the mildest January nights. Warm coats and heating bills mark the months from November to March, when means dip under 10°C.
Figures from Météo-France’s Bagatelle station, 12 km east.
A year in Saint-Germain-en-Laye at a glance
Each month’s typical high and low in °C, at the Bagatelle station.
What a year in Saint-Germain-en-Laye feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Bagatelle.
About 639 mm of rain a year
May is the wettest month and February the driest. About 18 days a year bring 10 mm or more. 79th wettest of 95 towns of 2,500+ in Yvelines.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Trappes
36 frosts and 70 days of 25°C a year
On about 36 nights a year the air drops to 0°C or below, and on about 3 days it stays below freezing all day. About 70 days a year reach 25°C, and 20 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Bagatelle: 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 Bagatelle
Bagatelle is 12 km east of Saint-Germain-en-Laye. Every figure on this page is the station’s, not a measurement in Saint-Germain-en-Laye itself.
| Station (Météo-France number) | Bagatelle (75116002) |
| Distance from the town | 12 km east |
| Station altitude | 36 m |
| Town altitude (its center) | 83 m |
| Period | 1991–2015 (the station’s own record) |
| Sunshine measured at | Trappes, 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 Saint-Germain-en-Laye 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. 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 |
|---|---|---|---|---|
| Saint-Germain-en-Laye | Bagatelle | 26.4°C | 2.7°C | 639 mm |
| Le Pecq 1.8 km | same station | 26.4°C about the same | 2.7°C about the same | 639 mm |
| Mareil-Marly 1.8 km | Trappes | 24.6°C 1.8°C cooler | 1.9°C 0.8°C colder | 686 mm |
| Marly-le-Roi 2.7 km | same station | 26.4°C about the same | 2.7°C about the same | 639 mm |
| Chambourcy 3 km | Trappes | 24.6°C 1.8°C cooler | 1.9°C 0.8°C colder | 686 mm |
| Le Port-Marly 3 km | same station | 26.4°C about the same | 2.7°C about the same | 639 mm |
| L'Étang-la-Ville 3.3 km | Trappes | 24.6°C 1.8°C cooler | 1.9°C 0.8°C colder | 686 mm |
Saint-Germain-en-Laye weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Bagatelle station; sunshine at Trappes.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 8.1°C | 2.7°C | 5.4°C | 51 mm | 57 |
| February | 9.3°C | 2.3°C | 5.8°C | 45 mm | 81 |
| March | 13.7°C | 4.3°C | 9.1°C | 46 mm | 134 |
| April | 17.3°C | 6.4°C | 11.7°C | 45 mm | 176 |
| May | 20.9°C | 10.0°C | 15.5°C | 70 mm | 202 |
| June | 24.1°C | 12.9°C | 18.6°C | 53 mm | 210 |
| July | 26.4°C | 14.9°C | 20.6°C | 51 mm | 222 |
| August | 26.3°C | 14.5°C | 20.4°C | 55 mm | 216 |
| September | 22.3°C | 11.4°C | 16.9°C | 46 mm | 177 |
| October | 17.2°C | 8.7°C | 12.8°C | 55 mm | 117 |
| November | 11.4°C | 5.1°C | 8.3°C | 58 mm | 68 |
| December | 8.0°C | 2.7°C | 5.3°C | 64 mm | 55 |
| Year | 17.1°C | 8.0°C | 12.5°C | 639 mm | 1,714 |
Where Saint-Germain-en-Laye’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Bagatelle, 12 km away: statistics for 1991–2020 (the station’s own years, 1991–2015, where its record is shorter).
- 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, 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 Yvelines.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Saint-Germain-en-Laye’s climate
How warm does Saint-Germain-en-Laye get in summer?
July is the warmest month, with average highs of 26.4°C. About 70 days a year reach 25°C, more than 62% of mainland French towns, and about 20 reach 30°C.
How cold does Saint-Germain-en-Laye get in winter?
February nights average 2.3°C. The air drops to 0°C or below on about 36 nights a year, and about 3 days a year stay below freezing all day.
How much rain does Saint-Germain-en-Laye get?
About 639 mm a year, less than 85% of mainland French towns. May is the wettest month (70 mm) and February the driest (45 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Trappes (15 km away), averages 1,714 hours of sunshine a year.
Are these figures for Saint-Germain-en-Laye itself?
No: they are the normals of the Météo-France station matched to Saint-Germain-en-Laye, Bagatelle, 12 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 BAGATELLE, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Saint-Germain-en-Laye →
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.