January in Blacy bites harder than in 82% of mainland French towns
Peak summer warmth arrives in July, with afternoons near 26.0°C. Wet weather is most frequent in May and least in March. Frost greets about 61 mornings a year, so leave time to clear the car.
Figures from Météo-France’s Semur-en-Auxois station, 24 km south-east.
A year in Blacy at a glance
Each month’s typical high and low in °C, at the Semur-en-Auxois station.
What a year in Blacy feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Semur-en-Auxois.
About 778 mm of rain a year
May is the wettest month and March the driest. About 22 days a year bring 10 mm or more. The wettest of 19 towns of 2,500+ in Yonne.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Châtillon/Seine
A frosty town: 61 frosts and 58 days of 25°C a year
On about 61 nights a year the air drops to 0°C or below, and on about 7 days it stays below freezing all day. About 58 days a year reach 25°C, and 19 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Semur-en-Auxois: 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 Semur-en-Auxois
Semur-en-Auxois is 24 km south-east of Blacy. Every figure on this page is the station’s, not a measurement in Blacy itself.
| Station (Météo-France number) | Semur-en-Auxois (21603001) |
| Distance from the town | 24 km south-east |
| Station altitude | 314 m |
| Town altitude (its center) | 284 m |
| Period | 1991–2020 |
| Nearest station of any kind | 9.5 km |
| Sunshine measured at | Châtillon/Seine, 51 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 Blacy 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 Yonne.
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 |
|---|---|---|---|---|
| Blacy | Semur-en-Auxois | 26.0°C | 0.3°C | 778 mm |
| Avallon 14 km | Merry-sur-Yonne | 26.4°C about the same | 0.8°C 0.5°C milder | 777 mm |
| Montbard 23 km | Montbard | 26.3°C about the same | 0.5°C about the same | 854 mm |
| Semur-en-Auxois 24 km | same station | 26.0°C about the same | 0.3°C about the same | 778 mm |
Blacy weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Semur-en-Auxois station; sunshine at Châtillon/Seine.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 6.2°C | 0.3°C | 3.3°C | 62 mm | 67 |
| February | 7.6°C | 0.2°C | 3.9°C | 54 mm | 90 |
| March | 12.2°C | 2.4°C | 7.3°C | 53 mm | 148 |
| April | 15.5°C | 4.5°C | 10.0°C | 64 mm | 183 |
| May | 19.5°C | 8.3°C | 13.9°C | 77 mm | 201 |
| June | 23.5°C | 11.7°C | 17.6°C | 67 mm | 229 |
| July | 26.0°C | 13.7°C | 19.9°C | 63 mm | 235 |
| August | 25.9°C | 13.6°C | 19.7°C | 59 mm | 215 |
| September | 21.3°C | 10.0°C | 15.6°C | 65 mm | 176 |
| October | 16.2°C | 7.5°C | 11.8°C | 73 mm | 121 |
| November | 10.3°C | 3.6°C | 7.0°C | 74 mm | 72 |
| December | 7.0°C | 1.3°C | 4.1°C | 68 mm | 57 |
| Year | 15.9°C | 6.4°C | 11.2°C | 778 mm | 1,792 |
Where Blacy’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Semur-en-Auxois, 24 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, Châtillon/Seine, 51 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 Yonne.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Blacy’s climate
How warm does Blacy get in summer?
July is the warmest month, with average highs of 26.0°C. About 58 days a year reach 25°C, fewer than 56% of mainland French towns, and about 19 reach 30°C.
How cold does Blacy get in winter?
February nights average 0.2°C. The air drops to 0°C or below on about 61 nights a year, and about 7 days a year stay below freezing all day.
How much rain does Blacy get?
About 778 mm a year, more than 55% of mainland French towns. May is the wettest month (77 mm) and March the driest (53 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Châtillon/Seine (51 km away), averages 1,792 hours of sunshine a year.
Are these figures for Blacy itself?
No: they are the normals of the Météo-France station matched to Blacy, Semur-en-Auxois, 24 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 SEMUR EN AUXOIS_SAPC, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Blacy →
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.