Summer warmth: Cailly logs fewer 25-degree days than 91% of mainland French towns
The coldest hours of a January night bottom out at 1.6°C on average. Of the 76 towns of 2,500+ in Seine-Maritime, it is the wettest. Expect the heaviest rain in December and the lightest in April. From May to September, highs of 18–23°C make it easy to spend the day outdoors.
These are the figures of Météo-France’s Rouen-Boos station, 22 km south.
A year in Cailly at a glance
Each month’s typical high and low in °C, at the Rouen-Boos station.
What a year in Cailly feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Rouen-Boos.
About 848 mm of rain a year
December is the wettest month and April the driest. About 24 days a year bring 10 mm or more. The wettest of 76 towns of 2,500+ in Seine-Maritime.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Rouen-Boos
42 frosts and 31 days of 25°C a year
On about 42 nights a year the air drops to 0°C or below, and on about 4 days it stays below freezing all day. About 31 days a year reach 25°C, and 6 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Rouen-Boos: 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 Rouen-Boos
Rouen-Boos is 22 km south of Cailly. Every figure on this page is the station’s, not a measurement in Cailly itself.
| Station (Météo-France number) | Rouen-Boos (76116001) |
| Distance from the town | 22 km south |
| Station altitude | 156 m |
| Town altitude (its center) | 120 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 Cailly 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 Seine-Maritime.
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 |
|---|---|---|---|---|
| Cailly | Rouen-Boos | 23.4°C | 1.6°C | 848 mm |
| Quincampoix 7.6 km | same station | 23.4°C about the same | 1.6°C about the same | 848 mm |
| Buchy 8.8 km | same station | 23.4°C about the same | 1.6°C about the same | 848 mm |
| Isneauville 11 km | same station | 23.4°C about the same | 1.6°C about the same | 848 mm |
| Montville 12 km | Rouen - Jardin | 25.9°C 2.5°C warmer | 2.7°C 1.1°C milder | 818 mm |
| Houppeville 14 km | same station | 23.4°C about the same | 1.6°C about the same | 848 mm |
| Malaunay 15 km | Rouen - Jardin | 25.9°C 2.5°C warmer | 2.7°C 1.1°C milder | 818 mm |
Cailly weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Rouen-Boos station.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 6.9°C | 1.6°C | 4.3°C | 76 mm | 52 |
| February | 7.9°C | 1.6°C | 4.8°C | 65 mm | 77 |
| March | 11.4°C | 3.5°C | 7.5°C | 62 mm | 119 |
| April | 14.8°C | 5.2°C | 10.0°C | 56 mm | 165 |
| May | 17.9°C | 8.3°C | 13.1°C | 67 mm | 182 |
| June | 21.1°C | 11.1°C | 16.1°C | 64 mm | 197 |
| July | 23.4°C | 13.0°C | 18.2°C | 64 mm | 200 |
| August | 23.4°C | 13.1°C | 18.2°C | 70 mm | 190 |
| September | 20.1°C | 10.6°C | 15.3°C | 62 mm | 159 |
| October | 15.4°C | 8.0°C | 11.7°C | 79 mm | 108 |
| November | 10.4°C | 4.6°C | 7.5°C | 80 mm | 58 |
| December | 7.3°C | 2.1°C | 4.7°C | 102 mm | 49 |
| Year | 15.0°C | 6.9°C | 10.9°C | 848 mm | 1,554 |
Where Cailly’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Rouen-Boos, 22 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, Rouen-Boos, 22 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 Seine-Maritime.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Cailly’s climate
How warm does Cailly get in summer?
July is the warmest month, with average highs of 23.4°C. About 31 days a year reach 25°C, fewer than 91% of mainland French towns, and about 6 reach 30°C.
How cold does Cailly get in winter?
January nights average 1.6°C. The air drops to 0°C or below on about 42 nights a year, and about 4 days a year stay below freezing all day.
How much rain does Cailly get?
About 848 mm a year, more than 70% of mainland French towns. December is the wettest month (102 mm) and April the driest (56 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Rouen-Boos (22 km away), averages 1,554 hours of sunshine a year.
Are these figures for Cailly itself?
No: they are the normals of the Météo-France station matched to Cailly, Rouen-Boos, 22 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 ROUEN-BOOS, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Cailly →
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.