Lisbon vs Porto

Based on sunshine hours, rain days, comfortable temperatures, and humidity levels, Lisbon edges ahead as the better destination in September. Lisbon offers 11 hours of daily sunshine with only 4 rain days, while Porto sees 10 sunshine hours and 6 rain days.

Lisbon sits in the comfortable travel range at 25°C. Porto is also comfortable at 24°C.

For travelers who prioritize dry weather, Lisbon is the stronger choice in September. Lisbon receives 1 more hour of sunshine per day, which matters for sightseeing and outdoor activities.

Lisbon reaches an average high of 25°C (77°F) and drops to 18°C (64°F) at night during September. The daily temperature range is 7°C, meaning relatively stable temperatures from day to night.

Porto averages 24°C (75°F) for the high and 16°C (61°F) for the low, with a daily range of 8°C. The two cities feel quite similar in terms of temperature.

Both cities are in the Northern Hemisphere, so they share the same seasonal pattern in September.

Lisbon receives approximately 29 mm of rainfall across 4 rain days during September. Rain is occasional, so a light rain jacket should suffice.

Porto sees 64 mm over 6 rain days. That makes Lisbon the drier option by 2 rain days and 35 mm of total precipitation.

Both cities share similar humidity levels at 65%.