Climate averages 1991–2020
Lisbon weather
in September.
A warm, fairly dry month: the 3rd warmest and the 4th driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Lisbon: daytime highs average 24.4°C and nights cool to about 17.8°C. By daytime temperature it is the 3rd warmest of the 12 months.
Expect about 29 mm of rain on roughly 4 days, which makes September a fairly dry month (the 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 29 min on an average September day.
The nearest other city in this atlas is Amadora (8 km away). In September its highs average 24.3°C, about as warm as Lisbon, with 29 mm of rain.
Among the 12 cities listed in Portugal, Lisbon ranks 5th of 12 for the warmest September highs and joint 4th of 12 for the driest September (rainfall, lowest first). The mean September high of those 12 cities is 24.6°C; Lisbon is 0.2°C cooler than that mean.
From September to October, average highs fall by 3.5°C to 20.9°C, and monthly rainfall rises from 29 mm to 77 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
Lisbon climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 13.4°C9.1°C | 9.1°C | 68 | 8.9 | 9.810 h |
| February | 14.2°C9.2°C | 9.2°C | 52 | 7.6 | 10.711 h |
| March | 16.4°C10.8°C | 10.8°C | 53 | 8.1 | 11.912 h |
| April | 17.9°C12.2°C | 12.2°C | 51 | 8.4 | 13.213 h |
| May | 20.5°C14.3°C | 14.3°C | 42 | 5.9 | 14.314 h |
| June | 23.6°C16.6°C | 16.6°C | 9.9 | 2.1 | 14.815 h |
| July | 25.7°C18.0°C | 18.0°C | 2.0 | 0.6 | 14.615 h |
| August | 26.3°C18.6°C | 18.6°C | 4.1 | 1.0 | 13.714 h |
| September, selected | 24.4°C17.8°C | 17.8°C | 29 | 4.1 | 12.512 h |
| October | 20.9°C15.7°C | 15.7°C | 77 | 8.9 | 11.211 h |
| November | 16.7°C12.4°C | 12.4°C | 82 | 10.2 | 10.110 h |
| December | 14.3°C10.2°C | 10.2°C | 79 | 9.3 | 9.510 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
- Amadora in SeptemberPortugal · 8 kmHigh 24.3°C · Low 17.1°C · 29 mm rain
- Queluz in SeptemberPortugal · 10 kmHigh 22.9°C · Low 17.4°C · 29 mm rain
- Setúbal in SeptemberPortugal · 32 kmHigh 26.3°C · Low 16.9°C · 25 mm rain
- Leiria in SeptemberPortugal · 117 kmHigh 25.3°C · Low 15.7°C · 41 mm rain
- Coimbra in SeptemberPortugal · 176 kmHigh 26.3°C · Low 15.0°C · 49 mm rain
- Badajoz in SeptemberSpain · 190 kmHigh 29.0°C · Low 16.9°C · 23 mm rain
- Aveiro in SeptemberPortugal · 218 kmHigh 25.1°C · Low 15.8°C · 51 mm rain
- Faro in SeptemberPortugal · 218 kmHigh 24.3°C · Low 19.2°C · 19 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 Lisbon) is explained once on the Lisbon year overview and on the Sources, method and limits page.
Amadora and Queluz lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.