Sergy sits near the top of mainland French towns for rain, with 1,170 mm a year
Deep winter brings January lows near −1.0°C. Winter nights are cold: in January they are colder than in 94% of mainland French towns. No month is much wetter than another: December, the wettest, gets little more than February, the driest. Expect about 72 frosty starts a year, nights when the air falls below freezing.
These are the figures of Météo-France’s Archamps station, 17 km south-east.
A year in Sergy at a glance
Each month’s typical high and low in °C, at the Archamps station.
What a year in Sergy feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Archamps.
About 1,170 mm of rain a year
December is the wettest month and February the driest. About 41 days a year bring 10 mm or more. 11th wettest of 60 towns of 2,500+ in Ain.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Meythet
A frosty town: 72 frosts and 62 days of 25°C a year
On about 72 nights a year the air drops to 0°C or below, and on about 15 days it stays below freezing all day. About 62 days a year reach 25°C, and 17 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Archamps: 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 Archamps
Archamps is 17 km south-east of Sergy. Every figure on this page is the station’s, not a measurement in Sergy itself.
| Station (Météo-France number) | Archamps (74016001) |
| Distance from the town | 17 km south-east |
| Station altitude | 560 m |
| Town altitude (its center) | 483 m |
| Period | 1993–2020 (the station’s own record) |
| Nearest station of any kind | 8.9 km |
| Sunshine measured at | Meythet, 37 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 Sergy 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 Ain.
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 |
|---|---|---|---|---|
| Sergy | Archamps | 26.4°C | −1.0°C | 1,170 mm |
| Saint-Genis-Pouilly 2.3 km | Gaillard | 27.6°C 1.2°C warmer | −1.1°C about the same | 967 mm |
| Thoiry 2.4 km | same station | 26.4°C about the same | −1.0°C about the same | 1,170 mm |
| Prévessin-Moëns 6.2 km | Gaillard | 27.6°C 1.2°C warmer | −1.1°C about the same | 967 mm |
| Ségny 7.4 km | Gaillard | 27.6°C 1.2°C warmer | −1.1°C about the same | 967 mm |
| Ornex 7.7 km | Gaillard | 27.6°C 1.2°C warmer | −1.1°C about the same | 967 mm |
| Ferney-Voltaire 8.6 km | Gaillard | 27.6°C 1.2°C warmer | −1.1°C about the same | 967 mm |
Sergy weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Archamps station; sunshine at Meythet.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 4.2°C | −1.0°C | 1.6°C | 97 mm | 88 |
| February | 6.4°C | −0.6°C | 2.9°C | 79 mm | 113 |
| March | 11.2°C | 2.0°C | 6.6°C | 83 mm | 174 |
| April | 15.4°C | 4.7°C | 10.0°C | 94 mm | 191 |
| May | 19.9°C | 8.5°C | 14.2°C | 99 mm | 220 |
| June | 24.2°C | 12.1°C | 18.2°C | 97 mm | 256 |
| July | 26.4°C | 14.0°C | 20.2°C | 88 mm | 274 |
| August | 25.5°C | 13.8°C | 19.7°C | 100 mm | 249 |
| September | 20.4°C | 10.3°C | 15.4°C | 106 mm | 195 |
| October | 14.9°C | 7.1°C | 11.0°C | 112 mm | 141 |
| November | 8.3°C | 2.6°C | 5.5°C | 104 mm | 91 |
| December | 5.0°C | −0.2°C | 2.4°C | 113 mm | 78 |
| Year | 15.2°C | 6.1°C | 10.6°C | 1,170 mm | 2,069 |
Where Sergy’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Archamps, 17 km away: statistics for 1991–2020 (the station’s own years, 1993–2020, 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, Meythet, 37 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 Ain.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Sergy’s climate
How warm does Sergy get in summer?
July is the warmest month, with average highs of 26.4°C. About 62 days a year reach 25°C, more than 51% of mainland French towns, and about 17 reach 30°C.
How cold does Sergy get in winter?
January nights average −1.0°C. The air drops to 0°C or below on about 72 nights a year, and about 15 days a year stay below freezing all day.
How much rain does Sergy get?
About 1,170 mm a year, more than 95% of mainland French towns. December is the wettest month (113 mm) and February the driest (79 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Meythet (37 km away), averages 2,069 hours of sunshine a year.
Are these figures for Sergy itself?
No: they are the normals of the Météo-France station matched to Sergy, Archamps, 17 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 ARCHAMPS, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Sergy →
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.