Summer warmth: Castandet logs more 25-degree days than 89% of mainland French towns
The coldest hours of a January night bottom out at 2.3°C on average. From frosty January to warm July, readings climb 26°C. By rainfall alone, it ranks wetter than 87% of mainland French towns. Windscreens need scraping on about 37 mornings a year, the nights the air drops below 0°C.
Figures from Météo-France’s Grenade-sur-Ad station, 7.2 km west.
A year in Castandet at a glance
Each month’s typical high and low in °C, at the Grenade-sur-Ad station.
What a year in Castandet feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Grenade-sur-Ad.
About 1,010 mm of rain a year
November is the wettest month and July the driest. About 34 days a year bring 10 mm or more. 26th wettest of 35 towns of 2,500+ in Landes.
Rain by month
Millimeters
37 frosts and 103 days of 25°C a year
On about 37 nights a year the air drops to 0°C or below, and on about under 1 days it stays below freezing all day. About 103 days a year reach 25°C, and 39 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Grenade-sur-Ad: 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 Grenade-sur-Ad
Grenade-sur-Ad is 7.2 km west of Castandet. Every figure on this page is the station’s, not a measurement in Castandet itself.
| Station (Météo-France number) | Grenade-sur-Ad (40117001) |
| Distance from the town | 7.2 km west |
| Station altitude | 72 m |
| Town altitude (its center) | 104 m |
| Period | 1991–2020 |
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 Castandet 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 Landes.
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 |
|---|---|---|---|---|
| Castandet | Grenade-sur-Ad | 28.1°C | 2.3°C | 1,010 mm |
| Villeneuve-de-Marsan 9.5 km | same station | 28.1°C about the same | 2.3°C about the same | 1,010 mm |
| Aire-sur-l'Adour 14 km | same station | 28.1°C about the same | 2.3°C about the same | 1,010 mm |
| Mont-de-Marsan 14 km | Mont-de-Marsan | 27.8°C about the same | 2.1°C about the same | 918 mm |
| Saint-Pierre-du-Mont 15 km | Mont-de-Marsan | 27.8°C about the same | 2.1°C about the same | 918 mm |
| Saint-Sever 19 km | same station | 28.1°C about the same | 2.3°C about the same | 1,010 mm |
| Hagetmau 26 km | Urgons | 26.8°C 1.3°C cooler | 3.2°C 0.9°C milder | 1,009 mm |
Castandet weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Grenade-sur-Ad station.
| Month | High | Low | Mean | Rain |
|---|---|---|---|---|
| January | 11.0°C | 2.3°C | 6.6°C | 98 mm |
| February | 12.8°C | 2.3°C | 7.5°C | 76 mm |
| March | 16.6°C | 4.6°C | 10.6°C | 78 mm |
| April | 19.0°C | 7.0°C | 13.0°C | 92 mm |
| May | 22.7°C | 10.7°C | 16.7°C | 92 mm |
| June | 26.0°C | 14.0°C | 20.0°C | 72 mm |
| July | 28.1°C | 15.6°C | 21.8°C | 58 mm |
| August | 28.5°C | 15.4°C | 21.9°C | 64 mm |
| September | 25.4°C | 12.2°C | 18.8°C | 78 mm |
| October | 20.7°C | 9.5°C | 15.1°C | 87 mm |
| November | 14.6°C | 5.4°C | 10.0°C | 118 mm |
| December | 11.5°C | 3.0°C | 7.3°C | 99 mm |
| Year | 19.7°C | 8.5°C | 14.1°C | 1,010 mm |
Where Castandet’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Grenade-sur-Ad, 7.2 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.
- Comparisons: every town of 2,500 or more in mainland France, read the same way; the dots are the towns of 2,500+ in Landes.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Castandet’s climate
How warm does Castandet get in summer?
August is the warmest month, with average highs of 28.5°C. About 103 days a year reach 25°C, more than 89% of mainland French towns, and about 39 reach 30°C.
How cold does Castandet get in winter?
January nights average 2.3°C. The air drops to 0°C or below on about 37 nights a year, and about under 1 days a year stay below freezing all day.
How much rain does Castandet get?
About 1,010 mm a year, more than 87% of mainland French towns. November is the wettest month (118 mm) and July the driest (58 mm).
Are these figures for Castandet itself?
No: they are the normals of the Météo-France station matched to Castandet, Grenade-sur-Ad, 7.2 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 GRENADE-SUR-AD, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Castandet →
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.