Climate averages 1991–2020
Leiden weather
in September.
A mild, moderately wet month: the 4th warmest and the 10th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Leiden: daytime highs average 18.0°C and nights cool to about 12.9°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 87 mm of rain on roughly 13 days, which makes September a moderately wet month (the 10th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 43 min on an average September day.
The nearest other city in this atlas is Zoetermeer (11 km away). In September its highs average 18.3°C, about as warm as Leiden, with 69 mm of rain.
Among the 44 cities listed in the Netherlands, Leiden ranks 35th of 44 for the warmest September highs and 44th of 44 for the driest September (rainfall, lowest first). The mean September high of those 44 cities is 18.4°C; Leiden is 0.4°C cooler than that mean.
From September to October, average highs fall by 3.9°C to 14.1°C, and monthly rainfall rises from 87 mm to 93 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Leiden climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 6.0°C2.3°C | 2.3°C | 72 | 13.6 | 8.38 h |
| February | 6.4°C2.1°C | 2.1°C | 57 | 11.6 | 9.910 h |
| March | 9.0°C3.7°C | 3.7°C | 54 | 11.3 | 11.812 h |
| April | 12.5°C6.0°C | 6.0°C | 45 | 10.1 | 13.914 h |
| May | 15.8°C9.6°C | 9.6°C | 58 | 10.4 | 15.716 h |
| June | 18.4°C12.4°C | 12.4°C | 61 | 11.0 | 16.717 h |
| July | 20.6°C14.8°C | 14.8°C | 77 | 12.4 | 16.216 h |
| August | 20.8°C15.1°C | 15.1°C | 90 | 13.3 | 14.715 h |
| September, selected | 18.0°C12.9°C | 12.9°C | 87 | 13.0 | 12.713 h |
| October | 14.1°C9.6°C | 9.6°C | 93 | 14.0 | 10.711 h |
| November | 9.8°C6.1°C | 6.1°C | 83 | 15.3 | 8.99 h |
| December | 6.7°C3.3°C | 3.3°C | 84 | 14.6 | 7.88 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Zoetermeer in SeptemberThe Netherlands · 11 kmHigh 18.3°C · Low 12.5°C · 69 mm rain
- Alphen aan den Rijn in SeptemberThe Netherlands · 12 kmHigh 18.3°C · Low 12.1°C · 81 mm rain
- The Hague in SeptemberThe Netherlands · 16 kmHigh 18.1°C · Low 13.0°C · 74 mm rain
- Delft in SeptemberThe Netherlands · 19 kmHigh 18.3°C · Low 12.5°C · 74 mm rain
- Hoofddorp in SeptemberThe Netherlands · 21 kmHigh 17.9°C · Low 13.0°C · 81 mm rain
- Gouda in SeptemberThe Netherlands · 22 kmHigh 18.4°C · Low 12.0°C · 67 mm rain
- Rotterdam in SeptemberThe Netherlands · 26 kmHigh 18.5°C · Low 12.0°C · 69 mm rain
- Haarlem in SeptemberThe Netherlands · 27 kmHigh 17.7°C · Low 13.2°C · 84 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Leiden) is explained once on the Leiden year overview and on the Sources, method and limits page.