Few mainland French towns get more frosts than By
A typical January night drops to −3.1°C and a July afternoon reaches 25.7°C; 1,526 mm of rain falls in a year. It is a wet place: more rain falls here than on almost every mainland French town. The year swings widely: the coldest month’s nights and the warmest month’s afternoons are 29°C apart. None of its 6 nearest neighbors has colder January nights. These are the figures of Météo-France’s Besain station, 26 km south; at that distance they describe the area more than the town.
A year in By at a glance
Each month’s typical high and low in °C, at the Besain station.
What a year in By feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Besain.
About 1,526 mm of rain a year
November is the wettest month and July the driest. About 56 days a year bring 10 mm or more. 4th wettest of 34 towns of 2,500+ in Doubs.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Besançon
A frosty town: 116 frosts and 61 days of 25°C a year
On about 116 nights a year the air drops to 0°C or below, and on about 9 days it stays below freezing all day. About 61 days a year reach 25°C, and 17 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Besain: 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 Besain
Besain is 26 km south of By. Every figure on this page is the station’s, not a measurement in By itself.
| Station (Météo-France number) | Besain (39050001) |
| Distance from the town | 26 km south |
| Station altitude | 535 m |
| Town altitude (its center) | 574 m |
| Period | 1991–2020 |
| Nearest station of any kind | 8.4 km |
| Sunshine measured at | Besançon, 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 By 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 Doubs.
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 |
|---|---|---|---|---|
| By | Besain | 25.7°C | −3.1°C | 1,526 mm |
| Arbois 15 km | Arbois | 25.7°C about the same | 0.4°C 3.5°C milder | 1,203 mm |
| Saint-Vit 20 km | Dannemarie-sur- | 26.3°C 0.6°C warmer | −0.4°C 2.7°C milder | 1,067 mm |
| Ornans 22 km | Besançon | 25.7°C about the same | 0.1°C 3.2°C milder | 1,157 mm |
| Poligny 24 km | Arbois | 25.7°C about the same | 0.4°C 3.5°C milder | 1,203 mm |
| Besançon 27 km | Besançon | 25.7°C about the same | 0.1°C 3.2°C milder | 1,157 mm |
| Saône 29 km | Besançon | 25.7°C about the same | 0.1°C 3.2°C milder | 1,157 mm |
By weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Besain station; sunshine at Besançon.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 5.9°C | −3.1°C | 1.4°C | 133 mm | 68 |
| February | 7.2°C | −3.1°C | 2.0°C | 118 mm | 97 |
| March | 11.5°C | −0.6°C | 5.5°C | 120 mm | 153 |
| April | 15.4°C | 2.0°C | 8.7°C | 114 mm | 184 |
| May | 19.5°C | 6.2°C | 12.9°C | 140 mm | 208 |
| June | 23.4°C | 9.6°C | 16.5°C | 107 mm | 231 |
| July | 25.7°C | 11.3°C | 18.5°C | 104 mm | 249 |
| August | 25.3°C | 11.0°C | 18.2°C | 114 mm | 237 |
| September | 20.7°C | 7.5°C | 14.1°C | 117 mm | 184 |
| October | 16.0°C | 4.6°C | 10.3°C | 143 mm | 132 |
| November | 10.1°C | 0.5°C | 5.3°C | 159 mm | 75 |
| December | 6.6°C | −2.2°C | 2.2°C | 157 mm | 56 |
| Year | 15.6°C | 3.6°C | 9.6°C | 1,526 mm | 1,873 |
Where By’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Besain, 26 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, Besançon, 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 Doubs.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about By’s climate
How warm does By get in summer?
July is the warmest month, with average highs of 25.7°C. About 61 days a year reach 25°C, fewer than 50% of mainland French towns, and about 17 reach 30°C.
How cold does By get in winter?
January nights average −3.1°C. The air drops to 0°C or below on about 116 nights a year, and about 9 days a year stay below freezing all day.
How much rain does By get?
About 1,526 mm a year, more than almost every mainland French town. November is the wettest month (159 mm) and July the driest (104 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Besançon (27 km away), averages 1,873 hours of sunshine a year.
Are these figures for By itself?
No: they are the normals of the Météo-France station matched to By, Besain, 26 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 BESAIN, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for By →
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.