Lisbon Weather in September
Portugal · Mediterranean climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
September in Lisbon sees average temperatures ranging from a low of 17.5°C (63.5°F) to a high of 25.8°C (78.4°F), with a mean of 20.9°C (69.6°F). Compared to the annual average of 17.2°C (63.0°F), this month is 3.7°C warmer than the yearly norm. Precipitation averages 51.5mm, making it approximately 2.0mm wetter than the monthly average of 49.0mm. The city receives an average of 10.7 hours of sunshine per day during September, with relative humidity averaging 72.5%. Wind speeds reach an average maximum of 19.6 km/h. For travelers, this month offers a temperature experience in Lisbon, with wetter-than-average conditions compared to the rest of the year.
Lisbon's hills plus humidity make packing an art form. I showed up in July in linen — big mistake, the UV hits 9 and the city is essentially a suntrap. Pack breathable layers, a wide-brim hat, and the strongest SPF you own. My ideal window is mid-September to mid-October: 24°C, fewer crowds, and the Tagus breeze actually feels good. Skip February — it's wetter than you'd think. Tram 28 in summer is a sweatbox; ride it in November instead, when it's 16°C and the queues vanish.
September vs Adjacent Months
| Metric | August | September | October |
|---|---|---|---|
| Mean Temp | 22.5°C (72.5°F) | 20.9°C (69.6°F) | 18.9°C (66.0°F) |
| Rainfall | 1.0mm | 51.5mm | 98.7mm |
| Sunshine | 12.3 hrs | 10.7 hrs | 8.7 hrs |
| Humidity | 68.9% | 72.5% | 76.4% |
| Wind | 21.4 km/h | 19.6 km/h | 19.6 km/h |
| Rainy Days | 1.4 | 10.4 | 14.8 |
Seasonal Context
September falls in Autumn in the Northern Hemisphere. Autumn sees temperatures gradually cooling from summer highs. For travelers visiting Lisbon in September, the data indicates favorable conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Lisbon in September?
The average temperature in Lisbon during September ranges from 17.5°C (63.5°F) to 25.8°C (78.4°F), with a mean of 20.9°C (69.6°F).
How much does it rain in Lisbon in September?
Lisbon receives an average of 51.5mm of precipitation in September, spread across approximately 10.4 rainy days.
What should I pack for Lisbon in September?
Based on September weather data, pack layers including light jackets and t-shirts, plus an umbrella.
Is September a good time to visit Lisbon?
September is a good time to visit Lisbon, with comfortable temperatures and manageable rainfall.
Other Months for Lisbon
Cities with Similar September Climate (Mediterranean)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 38.72°, -9.14°. Timezone: Europe/Lisbon. Last updated: 2026-07-30.