Chélan has colder winter nights than 80% of mainland French towns
Météo-France’s Castelnau-Magnoac station, 8.2 km south: a typical January night drops to 0.5°C and a July afternoon reaches 26.4°C; 877 mm of rain falls in a year. Rain is plentiful here, more than falls on 74% of mainland French towns. Summers go the other way: about 73 days a year reach 25°C, more than in 67% of mainland French towns.
A year in Chélan at a glance
Each month’s typical high and low in °C, at the Castelnau-Magnoac station.
What a year in Chélan feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Castelnau-Magnoac.
About 877 mm of rain a year
May is the wettest month and August the driest. About 29 days a year bring 10 mm or more. The wettest of 11 towns of 2,500+ in Gers.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Campistrous
A frosty town: 51 frosts and 73 days of 25°C a year
On about 51 nights a year the air drops to 0°C or below, and on about 1 days it stays below freezing all day. About 73 days a year reach 25°C, and 22 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Castelnau-Magnoac: 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 Castelnau-Magnoac
Castelnau-Magnoac is 8.2 km south of Chélan. Every figure on this page is the station’s, not a measurement in Chélan itself.
| Station (Météo-France number) | Castelnau-Magnoac (65129003) |
| Distance from the town | 8.2 km south |
| Station altitude | 298 m |
| Town altitude (its center) | 245 m |
| Period | 1991–2020 |
| Sunshine measured at | Campistrous, 29 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 Chélan 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 Gers.
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 |
|---|---|---|---|---|
| Chélan | Castelnau-Magnoac | 26.4°C | 0.5°C | 877 mm |
| Mirande 22 km | Mirande | 27.8°C 1.4°C warmer | 1.9°C 1.4°C milder | 819 mm |
| Lannemezan 28 km | Campistrous | 23.7°C 2.7°C cooler | 1.1°C 0.6°C milder | 1,140 mm |
Chélan weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Castelnau-Magnoac station; sunshine at Campistrous.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 10.3°C | 0.5°C | 5.4°C | 77 mm | 108 |
| February | 11.5°C | 0.8°C | 6.2°C | 63 mm | 134 |
| March | 14.8°C | 3.2°C | 9.0°C | 72 mm | 164 |
| April | 16.9°C | 5.7°C | 11.3°C | 89 mm | 168 |
| May | 20.4°C | 9.4°C | 14.9°C | 101 mm | 184 |
| June | 24.1°C | 12.8°C | 18.5°C | 69 mm | 202 |
| July | 26.4°C | 14.6°C | 20.5°C | 64 mm | 210 |
| August | 26.8°C | 14.4°C | 20.6°C | 54 mm | 204 |
| September | 23.8°C | 11.1°C | 17.4°C | 57 mm | 192 |
| October | 19.5°C | 7.9°C | 13.7°C | 65 mm | 160 |
| November | 13.8°C | 3.7°C | 8.7°C | 92 mm | 118 |
| December | 11.2°C | 1.3°C | 6.3°C | 74 mm | 117 |
| Year | 18.3°C | 7.1°C | 12.7°C | 877 mm | 1,960 |
Where Chélan’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Castelnau-Magnoac, 8.2 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, Campistrous, 29 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 Gers.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Chélan’s climate
How warm does Chélan get in summer?
August is the warmest month, with average highs of 26.8°C. About 73 days a year reach 25°C, more than 67% of mainland French towns, and about 22 reach 30°C.
How cold does Chélan get in winter?
January nights average 0.5°C. The air drops to 0°C or below on about 51 nights a year, and about 1 days a year stay below freezing all day.
How much rain does Chélan get?
About 877 mm a year, more than 74% of mainland French towns. May is the wettest month (101 mm) and August the driest (54 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Campistrous (29 km away), averages 1,960 hours of sunshine a year.
Are these figures for Chélan itself?
No: they are the normals of the Météo-France station matched to Chélan, Castelnau-Magnoac, 8.2 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 CASTELNAU MAGNOAC, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Chélan →
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.