Less rain falls on Herly than on 86% of mainland French towns: 636 mm a year
Expect July afternoons of about 24.3°C. Warm afternoons come less often than in 82% of mainland French towns. Only 23°C separates winter nights from summer afternoons. The heating season runs November to April: each of those months averages under 10°C.
These are the figures of Météo-France’s Rouvroy-en-Santerre station, 13 km west.
A year in Herly at a glance
Each month’s typical high and low in °C, at the Rouvroy-en-Santerre station.
What a year in Herly feels like
Typical highs and lows by season and by month, from Météo-France’s 1991–2020 normals at Rouvroy-en-Santerre.
About 636 mm of rain a year
December is the wettest month and April the driest. About 15 days a year bring 10 mm or more. 23rd wettest of 24 towns of 2,500+ in Somme.
Rain by month
Millimeters
Sunshine by month
Hours of sunshine at Saint-Quentin
47 frosts and 38 days of 25°C a year
On about 47 nights a year the air drops to 0°C or below, and on about 6 days it stays below freezing all day. About 38 days a year reach 25°C, and 8 reach 30°C.
Day counts are Météo-France’s 1991–2020 normals at Rouvroy-en-Santerre: 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 Rouvroy-en-Santerre
Rouvroy-en-Santerre is 13 km west of Herly. Every figure on this page is the station’s, not a measurement in Herly itself.
| Station (Météo-France number) | Rouvroy-en-Santerre (80682001) |
| Distance from the town | 13 km west |
| Station altitude | 95 m |
| Town altitude (its center) | 75 m |
| Period | 1993–2020 (the station’s own record) |
| Sunshine measured at | Saint-Quentin, 25 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 Herly 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 Somme.
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 |
|---|---|---|---|---|
| Herly | Rouvroy-en-Santerre | 24.3°C | 1.4°C | 636 mm |
| Roye 8.8 km | same station | 24.3°C about the same | 1.4°C about the same | 636 mm |
| Rosières-en-Santerre 14 km | same station | 24.3°C about the same | 1.4°C about the same | 636 mm |
| Ham 15 km | Saint-Quentin | 24.0°C about the same | 1.1°C about the same | 683 mm |
| Péronne 20 km | Estrées-Mons-Inrae | 24.4°C about the same | 1.3°C about the same | 648 mm |
| Noyon 22 km | Chauny | 24.9°C 0.6°C warmer | 1.5°C about the same | 710 mm |
| Montdidier 25 km | Godenvillers | 25.4°C 1.1°C warmer | 1.1°C about the same | 702 mm |
Herly weather by month
Average daily high and low, mean temperature and rain, 1991–2020, at the Rouvroy-en-Santerre station; sunshine at Saint-Quentin.
| Month | High | Low | Mean | Rain | Sun (hours) |
|---|---|---|---|---|---|
| January | 6.2°C | 1.4°C | 3.8°C | 46 mm | 62 |
| February | 7.5°C | 1.7°C | 4.6°C | 43 mm | 79 |
| March | 11.2°C | 3.1°C | 7.2°C | 44 mm | 135 |
| April | 15.2°C | 4.4°C | 9.8°C | 39 mm | 183 |
| May | 18.5°C | 8.0°C | 13.3°C | 61 mm | 206 |
| June | 21.8°C | 10.6°C | 16.2°C | 55 mm | 208 |
| July | 24.3°C | 12.3°C | 18.3°C | 64 mm | 214 |
| August | 24.4°C | 12.3°C | 18.4°C | 62 mm | 207 |
| September | 20.5°C | 9.8°C | 15.1°C | 45 mm | 167 |
| October | 15.6°C | 7.5°C | 11.5°C | 58 mm | 116 |
| November | 10.1°C | 4.1°C | 7.1°C | 52 mm | 67 |
| December | 6.7°C | 2.0°C | 4.4°C | 65 mm | 54 |
| Year | 15.2°C | 6.4°C | 10.8°C | 636 mm | 1,696 |
Where Herly’s numbers come from
Averages over 30 years, not a forecast.
- Temperature, rain and day counts: Météo-France’s fiche climatologique for Rouvroy-en-Santerre, 13 km away: statistics for 1991–2020 (the station’s own years, 1993–2020, where its record is shorter).
- 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, Saint-Quentin, 25 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 Somme.
Météo-France fiches climatologiques · IGN RGE ALTI®. Licence Ouverte 2.0.
Questions about Herly’s climate
How warm does Herly get in summer?
August is the warmest month, with average highs of 24.4°C. About 38 days a year reach 25°C, fewer than 82% of mainland French towns, and about 8 reach 30°C.
How cold does Herly get in winter?
January nights average 1.4°C. The air drops to 0°C or below on about 47 nights a year, and about 6 days a year stay below freezing all day.
How much rain does Herly get?
About 636 mm a year, less than 86% of mainland French towns. December is the wettest month (65 mm) and April the driest (39 mm).
How sunny is it?
The nearest Météo-France station that records sunshine, Saint-Quentin (25 km away), averages 1,696 hours of sunshine a year.
Are these figures for Herly itself?
No: they are the normals of the Météo-France station matched to Herly, Rouvroy-en-Santerre, 13 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 ROUVROY-EN-SANTERRE, edited 15/10/2026); altitude: IGN, RGE ALTI®. Licence Ouverte 2.0. Today’s forecast for Herly →
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.