Hardly any mainland French towns collect less rain than Tréon: 572 mm a year
Peak summer warmth arrives in July, with afternoons near 25.5°C. From frosty January to warm July, readings climb 24°C. Warm afternoons come less often than in 72% of mainland French towns. Keep the boiler serviced for the months from November to April, which average under 10°C.
Figures from Météo-France’s Marville station, 4.3 km south-east.
A year in Tréon at a glance
Each month’s typical high and low in °C, at the Marville station.
What a year in Tréon feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Marville.
About 572 mm of rain a year
May is the wettest month and September the driest. About 14 days a year bring 10 mm or more. 30th wettest of 33 towns of 2,500+ in Eure-et-Loir.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Chartres
49 frosts and 48 days of 25°C a year
On about 49 nights a year the air drops to 0°C or below, and on about 5 days it stays below freezing all day. About 48 days a year reach 25°C, and 13 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Marville: 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 Marville
Marville is 4.3 km south-east of Tréon. Every figure on this page is the station’s, not a measurement in Tréon itself.
| Station (Météo-France number) | Marville (28239002) |
| Distance from the town | 4.3 km south-east |
| Station altitude | 153 m |
| Town altitude (its center) | 112 m |
| Period | 1991–2020 |
| Sunshine measured at | Chartres, 27 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 Tréon 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 Eure-et-Loir.
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 |
|---|---|---|---|---|
| Tréon | Marville | 25.5°C | 1.6°C | 572 mm |
| Vernouillet 5.6 km | same station | 25.5°C about the same | 1.6°C about the same | 572 mm |
| Dreux 7.4 km | same station | 25.5°C about the same | 1.6°C about the same | 572 mm |
| Saint-Rémy-sur-Avre 11 km | same station | 25.5°C about the same | 1.6°C about the same | 572 mm |
| Châteauneuf-en-Thymerais 12 km | Thimert | 26.0°C 0.5°C warmer | 1.7°C about the same | 635 mm |
| Saint-Lubin-des-Joncherets 13 km | same station | 25.5°C about the same | 1.6°C about the same | 572 mm |
| Nogent-le-Roi 15 km | Houx | 25.7°C about the same | 1.2°C about the same | 622 mm |
Tréon weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Marville station; sunshine at Chartres.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 6.7°C | 1.6°C | 4.1°C | 46 mm | 64 |
| February | 7.9°C | 1.3°C | 4.6°C | 41 mm | 88 |
| March | 11.8°C | 3.0°C | 7.4°C | 42 mm | 140 |
| April | 15.3°C | 4.4°C | 9.8°C | 40 mm | 184 |
| May | 18.9°C | 7.5°C | 13.2°C | 61 mm | 209 |
| June | 22.6°C | 10.5°C | 16.6°C | 52 mm | 222 |
| July | 25.5°C | 12.5°C | 19.0°C | 48 mm | 230 |
| August | 25.4°C | 12.6°C | 19.0°C | 46 mm | 220 |
| September | 21.2°C | 10.1°C | 15.7°C | 40 mm | 181 |
| October | 15.9°C | 7.8°C | 11.8°C | 52 mm | 118 |
| November | 10.4°C | 4.4°C | 7.4°C | 48 mm | 72 |
| December | 7.1°C | 2.0°C | 4.5°C | 56 mm | 60 |
| Year | 15.7°C | 6.5°C | 11.1°C | 572 mm | 1,787 |
Where Tréon’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Marville, 4.3 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, Chartres, 27 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 Eure-et-Loir.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Tréon’s climate
How warm does Tréon get in summer?
July is the warmest month, with average highs of 25.5°C. About 48 days a year reach 25°C, fewer than 72% of mainland French towns, and about 13 reach 30°C.
How cold does Tréon get in winter?
February nights average 1.3°C. The air drops to 0°C or below on about 49 nights a year, and about 5 days a year stay below freezing all day.
How much rain does Tréon get?
About 572 mm a year, less than 98% of mainland French towns. May is the wettest month (61 mm) and September the driest (40 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Chartres (27 km away), averages 1,787 hours of sunshine a year.
Are these figures for Tréon itself?
No: they are the normals of the Météo-France station matched to Tréon, Marville, 4.3 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 MARVILLE_SAPC, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Tréon →
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.