Nights stay kind in Saint-Jean-d'Illac each January, milder than in 88% of mainland French towns
Peak summer warmth arrives in July, with afternoons near 27.1°C. Expect the heaviest rain in November and the lightest in July. It is a wet place: more rain falls here than on 81% of mainland French towns. For walks and days out, the stretch from April to June and September to October brings highs of 18–25°C.
Figures from Météo-France’s Bordeaux-Mérignac station, 8.3 km east.
A year in Saint-Jean-d'Illac at a glance
Each month’s typical high and low in °C, at the Bordeaux-Mérignac station.
What a year in Saint-Jean-d'Illac feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Bordeaux-Mérignac.
About 925 mm of rain a year
November is the wettest month and July the driest. About 30 days a year bring 10 mm or more. 25th wettest of 113 towns of 2,500+ in Gironde.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Bordeaux-Mérignac
23 frosts and 82 days of 25°C a year
On about 23 nights a year the air drops to 0°C or below, and on about 1 days it stays below freezing all day. About 82 days a year reach 25°C, and 26 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Bordeaux-Mérignac: 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 Bordeaux-Mérignac
Bordeaux-Mérignac is 8.3 km east of Saint-Jean-d'Illac. Every figure on this page is the station’s, not a measurement in Saint-Jean-d'Illac itself.
| Station (Météo-France number) | Bordeaux-Mérignac (33281001) |
| Distance from the town | 8.3 km east |
| Station altitude | 47 m |
| Town altitude (its center) | 47 m |
| Period | 1991–2020 |
| Sunshine measured at | the same station |
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-Jean-d'Illac 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 Gironde.
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-Jean-d'Illac | Bordeaux-Mérignac | 27.1°C | 3.7°C | 925 mm |
| Martignas-sur-Jalle 4.2 km | same station | 27.1°C about the same | 3.7°C about the same | 925 mm |
| Cestas 11 km | same station | 27.1°C about the same | 3.7°C about the same | 925 mm |
| Saint-Médard-en-Jalles 11 km | same station | 27.1°C about the same | 3.7°C about the same | 925 mm |
| Pessac 11 km | same station | 27.1°C about the same | 3.7°C about the same | 925 mm |
| Le Haillan 12 km | same station | 27.1°C about the same | 3.7°C about the same | 925 mm |
| Mérignac 12 km | same station | 27.1°C about the same | 3.7°C about the same | 925 mm |
Saint-Jean-d'Illac weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Bordeaux-Mérignac station.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 10.5°C | 3.7°C | 7.1°C | 87 mm | 90 |
| February | 12.0°C | 3.6°C | 7.8°C | 67 mm | 117 |
| March | 15.5°C | 5.8°C | 10.7°C | 63 mm | 170 |
| April | 18.0°C | 8.0°C | 13.0°C | 76 mm | 186 |
| May | 21.7°C | 11.4°C | 16.6°C | 71 mm | 221 |
| June | 25.0°C | 14.6°C | 19.8°C | 70 mm | 238 |
| July | 27.1°C | 16.2°C | 21.7°C | 49 mm | 256 |
| August | 27.6°C | 16.3°C | 21.9°C | 57 mm | 249 |
| September | 24.2°C | 13.3°C | 18.8°C | 81 mm | 209 |
| October | 19.6°C | 10.7°C | 15.2°C | 83 mm | 150 |
| November | 14.1°C | 6.7°C | 10.4°C | 115 mm | 100 |
| December | 11.0°C | 4.4°C | 7.7°C | 106 mm | 84 |
| Year | 18.9°C | 9.6°C | 14.2°C | 925 mm | 2,070 |
Where Saint-Jean-d'Illac’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Bordeaux-Mérignac, 8.3 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, Bordeaux-Mérignac, 8.3 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 Gironde.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Saint-Jean-d'Illac’s climate
How warm does Saint-Jean-d'Illac get in summer?
August is the warmest month, with average highs of 27.6°C. About 82 days a year reach 25°C, more than 73% of mainland French towns, and about 26 reach 30°C.
How cold does Saint-Jean-d'Illac get in winter?
February nights average 3.6°C. The air drops to 0°C or below on about 23 nights a year, and about 1 days a year stay below freezing all day.
How much rain does Saint-Jean-d'Illac get?
About 925 mm a year, more than 81% of mainland French towns. November is the wettest month (115 mm) and July the driest (49 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Bordeaux-Mérignac (8.3 km away), averages 2,070 hours of sunshine a year.
Are these figures for Saint-Jean-d'Illac itself?
No: they are the normals of the Météo-France station matched to Saint-Jean-d'Illac, Bordeaux-Mérignac, 8.3 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 BORDEAUX-MERIGNAC, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Saint-Jean-d'Illac →
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.