The best time to visit Nantes is May, June and September, when average highs sit in the comfortable range — 19.4 °C in May, 23.2 °C in June and 22.2 °C in September — with manageable rain days and plenty of brightness for exploring the Château des ducs de Bretagne. July and August are warm and sunny but mark peak season, with school-holiday crowds and higher prices. Winter is the quiet, low season, cooler and duller, with December the least sunny month of the year.
Best months MayJuneSeptember
Nantes month by month
Average highs and lows (°C), 2016–2025. Highlighted bars are the best months.
| Month | High | Low | Rain days | Sunshine | Days ≥30 °C | Sea | Crowds |
|---|---|---|---|---|---|---|---|
| January | 9.2 °C | 3.8 °C | 14 | ●●●●● | – | 9 °C | ●●●●● |
| February | 10.9 °C | 4.5 °C | 12 | ●●●●● | – | 9 °C | ●●●●● |
| March | 13 °C | 5.7 °C | 13 | ●●●●● | – | 11 °C | ●●●●● |
| April | 16.1 °C | 7.5 °C | 9 | ●●●●● | – | 13 °C | ●●●●● |
| May | 19.4 °C | 10.8 °C | 12 | ●●●●● | – | 17 °C | ●●●●● |
| June | 23.2 °C | 14.4 °C | 11 | ●●●●● | 2 | 20 °C | ●●●●● |
| July | 24.9 °C | 15.8 °C | 8 | ●●●●● | 4 | 21 °C | ●●●●● |
| August | 25.2 °C | 15.8 °C | 8 | ●●●●● | 5 | 21 °C | ●●●●● |
| September | 22.2 °C | 13.5 °C | 10 | ●●●●● | 2 | 19 °C | ●●●●● |
| October | 18 °C | 10.8 °C | 12 | ●●●●● | – | 17 °C | ●●●●● |
| November | 12.9 °C | 6.8 °C | 12 | ●●●●● | – | 13 °C | ●●●●● |
| December | 10.3 °C | 5.1 °C | 13 | ●●●●● | – | 10 °C | ●●●●● |
How the months are picked.A month qualifies when its average high sits in the comfortable 20–28 °C band (scored down towards 9 °C and 37 °C), rain days are few and sunshine hours are high — at least 78 % of the city's best-scoring month. July and August are then set aside as peak season (school-holiday crowds and prices) whenever at least three other months qualify; where summer is the only comfortable window they stay. Figures are ten-year averages (2016-01-01 to 2025-12-31) from ERA5 reanalysis data via Open-Meteo (CC BY 4.0) for the city centre coordinates. Sunshine is shown relative to the city's own year (modelled data overstates absolute hours).Heat and sea: days with a high of 30 °C or more are averaged over 2016–2025 (ERA5); sea-surface temperature is the monthly mean 2022–2025 at the nearest open-sea grid point within about 20 km (Open-Meteo Marine).Crowds:Relative to an average month in the same region (Eurostat nights spent at tourist accommodation, by NUTS 2 region and month) — a measure of season, not of how crowded one city is compared with another. Busiest month August, quietest January; NUTS 2 region FRG0, 2022–2025, Eurostat.
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When to go, and what to expect
Spring (Mar–May)
A top pick — mild, green and ahead of the summer rush.
Summer (Jun–Aug)
June is ideal; July and August suit those who don't mind crowds.
Autumn (Sep–Nov)
September is excellent; later autumn turns cooler and duller.
Winter (Dec–Feb)
Worth it mainly for museums, castle interiors and low-season calm.
Notable events
- Summer (July–August)
- Le Voyage à Nantes (city-wide art trail)
- Winter (late January–early February)
- La Folle Journée classical music festival
- July
- Bastille Day celebrations
- December
- Christmas market and festive lights
Frequently asked
Is Nantes too hot in August?
No. August highs average 25.2 °C with lows around 15.8 °C and only 8 rain days — warm and dry rather than sweltering, though it's the busiest time to visit.
What is the rainiest month in Nantes?
January is wettest with 14 rain days, closely followed by March and December at 13. May, June, July and August see fewer, with July and August at just 8.
Is winter worth visiting Nantes?
Winter is quiet and cool, with highs of 9.2 °C to 10.9 °C and December the least sunny month. It suits castle interiors, museums and festive events like La Folle Journée more than outdoor sightseeing.
Know when to go? Now decide where to stay — our Nantes area guide →
Areas of Nantes
Best time to visit near here
Sources
- Open-Meteo historical weather API — monthly climate normals, 2016–2025 (CC BY 4.0)
- ERA5 reanalysis (ECMWF / Copernicus) — the underlying temperature, precipitation and sunshine data
- ReasonStay methodology — how the best months are computed and checked
An independent guide to Nantes — honest, verified, no invented data. Climate figures: ERA5 via Open-Meteo, 2016–2025 averages; the best months are computed from them, not opinion.