Sercus gets fewer days of 25 degrees or more than 89% of mainland French towns
January mornings start at about 2.0°C. The gap between a January night and a July afternoon is 22°C. By rainfall alone, it ranks wetter than 66% of mainland French towns. Plan time outside from May to September, when highs sit at 19–24°C.
Figures from Météo-France’s Watten station, 22 km north-west.
A year in Sercus at a glance
Each month’s typical high and low in °C, at the Watten station.
What a year in Sercus feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Watten.
About 823 mm of rain a year
November is the wettest month and April the driest. About 23 days a year bring 10 mm or more. 7th wettest of 200 towns of 2,500+ in Nord.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Lille-Lesquin
41 frosts and 33 days of 25°C a year
On about 41 nights a year the air drops to 0°C or below, and on about 3 days it stays below freezing all day. About 33 days a year reach 25°C, and 7 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Watten: 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 Watten
Watten is 22 km north-west of Sercus. Every figure on this page is the station’s, not a measurement in Sercus itself.
| Station (Météo-France number) | Watten (59647001) |
| Distance from the town | 22 km north-west |
| Station altitude | 7 m |
| Town altitude (its center) | 52 m |
| Period | 1991–2020 |
| Nearest station of any kind | 15 km |
| Sunshine measured at | Lille-Lesquin, 48 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 Sercus 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 Nord.
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 |
|---|---|---|---|---|
| Sercus | Watten | 23.7°C | 2.0°C | 823 mm |
| Morbecque 5.5 km | same station | 23.7°C about the same | 2.0°C about the same | 823 mm |
| Hazebrouck 6.1 km | same station | 23.7°C about the same | 2.0°C about the same | 823 mm |
| Aire-sur-la-Lys 8.6 km | same station | 23.7°C about the same | 2.0°C about the same | 823 mm |
| Isbergues 10 km | same station | 23.7°C about the same | 2.0°C about the same | 823 mm |
| Saint-Venant 11 km | same station | 23.7°C about the same | 2.0°C about the same | 823 mm |
| Arques 11 km | same station | 23.7°C about the same | 2.0°C about the same | 823 mm |
Sercus weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Watten station; sunshine at Lille-Lesquin.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 7.6°C | 2.0°C | 4.8°C | 70 mm | 62 |
| February | 8.5°C | 2.0°C | 5.3°C | 58 mm | 74 |
| March | 11.7°C | 3.5°C | 7.6°C | 50 mm | 127 |
| April | 15.5°C | 5.1°C | 10.3°C | 44 mm | 176 |
| May | 18.6°C | 8.3°C | 13.5°C | 56 mm | 196 |
| June | 21.3°C | 11.2°C | 16.3°C | 59 mm | 202 |
| July | 23.7°C | 13.4°C | 18.5°C | 67 mm | 210 |
| August | 23.8°C | 13.4°C | 18.6°C | 73 mm | 197 |
| September | 20.7°C | 10.8°C | 15.7°C | 72 mm | 155 |
| October | 16.1°C | 8.1°C | 12.1°C | 84 mm | 115 |
| November | 11.1°C | 5.0°C | 8.1°C | 97 mm | 62 |
| December | 7.9°C | 2.6°C | 5.2°C | 93 mm | 53 |
| Year | 15.5°C | 7.1°C | 11.3°C | 823 mm | 1,627 |
Where Sercus’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Watten, 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, Lille-Lesquin, 48 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 Nord.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Sercus’s climate
How warm does Sercus get in summer?
August is the warmest month, with average highs of 23.8°C. About 33 days a year reach 25°C, fewer than 89% of mainland French towns, and about 7 reach 30°C.
How cold does Sercus get in winter?
January nights average 2.0°C. The air drops to 0°C or below on about 41 nights a year, and about 3 days a year stay below freezing all day.
How much rain does Sercus get?
About 823 mm a year, more than 66% of mainland French towns. November is the wettest month (97 mm) and April the driest (44 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Lille-Lesquin (48 km away), averages 1,627 hours of sunshine a year.
Are these figures for Sercus itself?
No: they are the normals of the Météo-France station matched to Sercus, Watten, 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 WATTEN, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Sercus →
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.