Guyancourt Weather in September
Guyancourt in September
The short of it: Guyancourt in September averages a high of 21 °C (69 °F) and a low of 11 °C (52 °F), with 47 mm (1.9 in) of rain and about 12 h 30 min of daylight. Rated 4 of 5 for a visit; the best months are June and July. Source: TerraClimate climate normals, 1991–2020.
Average high 21° · low 11° · rain 47 mm · daylight 12 h 30 min
✦✦✦✦ Recommended for a visit · best months: June & July
Thirty years of records give Guyancourt an average September high of 21°, a low of 11° and some 47 mm of rain. The year turns hard here: highs drop 4° from August to about 21°, with nights near 11°. Rain is modest, about 47 mm, the 9th wettest month.
The sun is up for about 12 h 30 min in mid-September, 111 minutes less than a month before.
For the traveller: pack light clothes and a jacket for the evening. The Almanac rates September 4 of 5 for a visit; the finest months here are June and July.
Against its neighbours, Guyancourt runs cooler than most and wetter than most in September. Saint-Quentin-en-Yvelines, 4 km to the W, sees much the same highs.
September in Guyancourt, by the numbers
- Warmth rank
- 4th warmest of 12
- Rain rank
- 9th wettest of 12
- Versus August
- 4° colder, 4.0 mm less rain
- Versus October
- 5° warmer
- Day–night spread
- 10°
- Snow season
- seldom any
- Daylight, mid-month
- 12 h 30 min
- Average wind
- 13 km/h
Neighbouring Towns
September averages · distance by the crow’s flight| Town | Distance | High | Low | Rain |
|---|---|---|---|---|
| Saint-Quentin-en-YvelinesÎle-de-France | 4 km W | 21° | 11° | 47 mm |
| VersaillesÎle-de-France | 6 km NE | 21° | 11° | 46 mm |
| Boulogne-BillancourtÎle-de-France | 14 km ENE | 22° | 12° | 43 mm |
| Rueil-MalmaisonÎle-de-France | 14 km NE | 22° | 12° | 43 mm |
| ClamartÎle-de-France | 15 km ENE | 21° | 12° | 45 mm |
| Issy-les-MoulineauxÎle-de-France | 16 km ENE | 21° | 12° | 45 mm |
| NanterreÎle-de-France | 16 km NE | 22° | 12° | 43 mm |
| AntonyÎle-de-France | 16 km E | 22° | 12° | 46 mm |