How warm is it in Lisbon in September?

Daytime highs averaged 22.6 °C, night-time lows 17.9 °C. The highest value of the past 10 years was 31.3 °C (3 Sep 2026), the lowest 14.5 °C (23 Sep 2025).

How often does it rain in Lisbon in September?

On average there were 4.3 rain days (at least 1 mm) with 22.3 mm of precipitation in total. In 1 of 10 years there was no rain day at all.

🇵🇹 Weather in Lisbon in September

This is what the weather in Lisbon (Portugal) was like in September in 2017–2026.

Key facts at a glance

Prevailing weather: Partly cloudy

Avg. daytime high

22.6 °C

21.5 °C – 24.5 °C

Avg. night-time low

17.9 °C

16.3 °C – 19.0 °C

Avg. rain days in period

4.3

14 % of days · ≥ 1.0 mm

Avg. precipitation in period

22.3 mm

0.4 mm – 63.7 mm

Avg. sunshine per day

n/a

Sunshine duration is not available from this data source.

Avg. sea temperature

–

Sea temperature unavailable for today (daily limit).

Extremes: Highest temperature 31.3 °C (3 Sep 2026) · Lowest temperature 14.5 °C (23 Sep 2025) · Avg. daily peak wind 24 km/h

Weather mix of all days

83Sunny
122Partly cloudy
24Cloudy
31Light rain
12Rain

Summary

On average 22.6 °C during the day and 17.9 °C at night.
On average 4.3 rain days (Rain day = at least 1.0 mm of precipitation) with 22.3 mm of precipitation in total.
In 1 of 10 years there was not a single rain day.
Prevailing: Partly cloudy.
Warmest year: 2026 (avg. 24.5 °C), coolest: 2017 (avg. 21.5 °C).
Wettest year: 2023 (63.7 mm), driest: 2017 (0.4 mm).
Extremes: 31.3 °C on 3 Sep 2026 and 14.5 °C on 23 Sep 2025.

Overall values from all 10 years. How is this calculated?

Temperatures per year

Average over your travel period

Precipitation & rain days

Year by year

2026
Avg. max24.5°Avg. min18.6°
Rain days
2 Rain days
Precipitation
3.6 mm
Avg. sunshine per day
n/a
Sea temperature
–
Max 31.3 °C · Min 16.7 °C
2025
Avg. max22.2°Avg. min17.2°
Rain days
2 Rain days
Precipitation
12.0 mm
Avg. cloud cover
43 % cloudy
Sea temperature
–
Max 23.9 °C · Min 14.5 °C
2024
Avg. max21.7°Avg. min16.9°
Rain days
3 Rain days
Precipitation
9.2 mm
Avg. cloud cover
36 % cloudy
Sea temperature
–
Max 26.7 °C · Min 14.7 °C
2023
Avg. max22.5°Avg. min18.5°
Rain days
12 Rain days
Precipitation
63.7 mm
Avg. cloud cover
47 % cloudy
Sea temperature
–
Max 27.8 °C · Min 16.7 °C
2022
Avg. max22.6°Avg. min19.0°
Rain days
9 Rain days
Precipitation
52.5 mm
Avg. cloud cover
42 % cloudy
Sea temperature
–
Max 27.0 °C · Min 15.7 °C
2021
Avg. max22.5°Avg. min18.7°
Rain days
8 Rain days
Precipitation
34.0 mm
Avg. cloud cover
42 % cloudy
Sea temperature
–
Max 23.9 °C · Min 16.2 °C
2020
Avg. max22.4°Avg. min18.1°
Rain days
4 Rain days
Precipitation
27.3 mm
Avg. cloud cover
53 % cloudy
Sea temperature
–
Max 25.8 °C · Min 16.4 °C
2019
Avg. max22.6°Avg. min17.6°
Rain days
2 Rain days
Precipitation
15.2 mm
Avg. cloud cover
42 % cloudy
Sea temperature
–
Max 25.7 °C · Min 15.6 °C
2018
Avg. max23.4°Avg. min18.0°
Rain days
1 Rain days
Precipitation
4.8 mm
Avg. cloud cover
51 % cloudy
Sea temperature
–
Max 26.9 °C · Min 16.9 °C
2017
Avg. max21.5°Avg. min16.3°
Rain days
0 Rain days
Precipitation
0.4 mm
Avg. cloud cover
41 % cloudy
Sea temperature
–
Max 25.9 °C · Min 14.8 °C

Frequently asked questions

How warm is it in Lisbon in September?: Daytime highs averaged 22.6 °C, night-time lows 17.9 °C. The highest value of the past 10 years was 31.3 °C (3 Sep 2026), the lowest 14.5 °C (23 Sep 2025).
How often does it rain in Lisbon in September?: On average there were 4.3 rain days (at least 1 mm) with 22.3 mm of precipitation in total. In 1 of 10 years there was no rain day at all.

Check your exact travel dates

Choose your travel period – we show the weather for exactly those days.

Data sources

Weather data: Data obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program
Reanalysis (weather model constrained by observations) on a coarse grid of about 50 km. Values represent a large area and can differ from local conditions, especially on islands, coasts and in mountains. No sunshine duration.
Reanalysis (weather model constrained by observations)
Reanalysis values represent a grid cell (approx. 25–50 km) and may differ from local measurements on coasts, islands and in mountains.
Sea temperature: MUR SST data were provided by JPL under support by NASA MEaSUREs program; accessed via NOAA CoastWatch ERDDAP
Daily multi-scale ultra-high resolution (≈ 1 km) analysis of satellite measurements (infrared, microwave) and in-situ data. Represents the foundation temperature below the daily warm surface layer. (Satellite and in-situ analysis)
Place search: Natural Earth (public domain) · GeoNames (CC BY 4.0) / OpenStreetMap (ODbL)