Midwinter lows in Saint-Ost sink below those of 80% of mainland French towns
High summer brings afternoon highs near 26.4°C. Of the 11 towns of 2,500+ in Gers, it is the wettest. Only 26°C separates winter nights from summer afternoons. Central heating does most of its work from November to March, in months below 10°C on average.
These are the figures of Météo-France’s Castelnau-Magnoac station, 12 km south.
A year in Saint-Ost at a glance
Each month’s typical high and low in °C, at the Castelnau-Magnoac station.
What a year in Saint-Ost 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 12 km south of Saint-Ost. Every figure on this page is the station’s, not a measurement in Saint-Ost itself.
| Station (Météo-France number) | Castelnau-Magnoac (65129003) |
| Distance from the town | 12 km south |
| Station altitude | 298 m |
| Town altitude (its center) | 247 m |
| Period | 1991–2020 |
| Nearest station of any kind | 9.7 km |
| 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 Saint-Ost 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 |
|---|---|---|---|---|
| Saint-Ost | Castelnau-Magnoac | 26.4°C | 0.5°C | 877 mm |
| Mirande 16 km | Mirande | 27.8°C 1.4°C warmer | 1.9°C 1.4°C milder | 819 mm |
| Pavie 28 km | Auch | 27.8°C 1.4°C warmer | 1.6°C 1.1°C milder | 696 mm |
| Lannemezan 29 km | Campistrous | 23.7°C 2.7°C cooler | 1.1°C 0.6°C milder | 1,140 mm |
Saint-Ost 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 Saint-Ost’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Castelnau-Magnoac, 12 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 Saint-Ost’s climate
How warm does Saint-Ost 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 Saint-Ost 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 Saint-Ost 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 Saint-Ost itself?
No: they are the normals of the Météo-France station matched to Saint-Ost, Castelnau-Magnoac, 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 CASTELNAU MAGNOAC, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Saint-Ost →
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.