Erny-Saint-Julien has some of the coolest summers among mainland French towns
The coldest hours of a January night bottom out at 1.6°C on average. Rain peaks in December and eases off in April. Its yearly rainfall tops that of 89% of mainland French towns. Comfortable outdoor weather lasts from June to September, with highs of 19–22°C.
Figures from Météo-France’s Radinghem station, 11 km west.
A year in Erny-Saint-Julien at a glance
Each month’s typical high and low in °C, at the Radinghem station.
What a year in Erny-Saint-Julien feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Radinghem.
About 1,038 mm of rain a year
December is the wettest month and April the driest. About 34 days a year bring 10 mm or more. 19th wettest of 131 towns of 2,500+ in Pas-de-Calais.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Le-Touquet
39 frosts and 21 days of 25°C a year
On about 39 nights a year the air drops to 0°C or below, and on about 6 days it stays below freezing all day. About 21 days a year reach 25°C, and 4 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Radinghem: 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 Radinghem
Radinghem is 11 km west of Erny-Saint-Julien. Every figure on this page is the station’s, not a measurement in Erny-Saint-Julien itself.
| Station (Météo-France number) | Radinghem (62685001) |
| Distance from the town | 11 km west |
| Station altitude | 115 m |
| Town altitude (its center) | 81 m |
| Period | 1991–2020 |
| Sunshine measured at | Le-Touquet, 45 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 Erny-Saint-Julien 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 Pas-de-Calais.
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 |
|---|---|---|---|---|
| Erny-Saint-Julien | Radinghem | 22.0°C | 1.6°C | 1,038 mm |
| Aire-sur-la-Lys 12 km | Watten | 23.7°C 1.7°C warmer | 2.0°C about the same | 823 mm |
| Wizernes 14 km | Watten | 23.7°C 1.7°C warmer | 2.0°C about the same | 823 mm |
| Blendecques 15 km | Watten | 23.7°C 1.7°C warmer | 2.0°C about the same | 823 mm |
| Isbergues 15 km | Watten | 23.7°C 1.7°C warmer | 2.0°C about the same | 823 mm |
| Burbure 16 km | Fiefs | 22.7°C 0.7°C warmer | 1.1°C 0.5°C colder | 1,071 mm |
| Lillers 16 km | Fiefs | 22.7°C 0.7°C warmer | 1.1°C 0.5°C colder | 1,071 mm |
Erny-Saint-Julien weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Radinghem station; sunshine at Le-Touquet.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 6.4°C | 1.6°C | 4.0°C | 98 mm | 62 |
| February | 7.1°C | 1.6°C | 4.4°C | 85 mm | 78 |
| March | 10.2°C | 3.3°C | 6.8°C | 72 mm | 133 |
| April | 13.8°C | 5.0°C | 9.4°C | 60 mm | 190 |
| May | 16.8°C | 8.0°C | 12.4°C | 70 mm | 210 |
| June | 19.6°C | 10.8°C | 15.2°C | 70 mm | 220 |
| July | 22.0°C | 12.9°C | 17.4°C | 73 mm | 225 |
| August | 22.2°C | 13.1°C | 17.7°C | 84 mm | 205 |
| September | 19.0°C | 10.8°C | 14.9°C | 77 mm | 161 |
| October | 14.7°C | 8.1°C | 11.4°C | 108 mm | 111 |
| November | 9.9°C | 4.8°C | 7.4°C | 119 mm | 63 |
| December | 6.9°C | 2.2°C | 4.5°C | 124 mm | 53 |
| Year | 14.0°C | 6.8°C | 10.5°C | 1,038 mm | 1,710 |
Where Erny-Saint-Julien’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Radinghem, 11 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, Le-Touquet, 45 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 Pas-de-Calais.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Erny-Saint-Julien’s climate
How warm does Erny-Saint-Julien get in summer?
August is the warmest month, with average highs of 22.2°C. About 21 days a year reach 25°C, fewer than 95% of mainland French towns, and about 4 reach 30°C.
How cold does Erny-Saint-Julien get in winter?
January nights average 1.6°C. The air drops to 0°C or below on about 39 nights a year, and about 6 days a year stay below freezing all day.
How much rain does Erny-Saint-Julien get?
About 1,038 mm a year, more than 89% of mainland French towns. December is the wettest month (124 mm) and April the driest (60 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Le-Touquet (45 km away), averages 1,710 hours of sunshine a year.
Are these figures for Erny-Saint-Julien itself?
No: they are the normals of the Météo-France station matched to Erny-Saint-Julien, Radinghem, 11 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 RADINGHEM, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Erny-Saint-Julien →
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.