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September catches travellers who assume summer ends on the first of the month. Porto weather september stays warm by day, and the sun still shines for 224 hours, but rain begins its return. For the river and the Douro Valley it remains a strong month. The daytime high of 24.1 °C is only 1.6 degrees below August's, while rain at 71.9 mm is more than double August's, so a September week usually mixes warm dry days with a few wet ones.
The river and the valley, for the drier days of the month.
Our pickPorto: Six Bridges Cruise
About 50 minutes on the river under the six bridges
A first look at the city from the water
Porto: Douro Valley with Lunch (Optional), Tastings & Cruise
A full day in the valley with tastings and a cruise; lunch optional
A dry day for the Douro
Still warm, a little wetter
The average weather Porto Portugal September brings is a high of 24.1 °C (75.4 °F), a low of 14.7 °C (58.5 °F) and 71.9 mm (2.8 in) of rain. Highs are barely below July's; rain is more than three times July's 20.4 mm (0.8 in).
That rain arrives as occasional wet days rather than a change of season. Plan outdoor outings with a little flexibility, and read the IPMA forecast a few days ahead.
September is a transition month in Porto, and its averages show warmth holding while rain begins to come back. The daytime high of 24.1 °C is only 1.6 degrees below August's peak, nights at 14.7 °C stay mild, and 224 hours of sunshine is still more than any month from October to April.
Rain at 71.9 mm is the figure that has changed most, more than double August's 32.9 mm, which means some wet days are part of the month.
September stays warm, with a little more rain than August.Towards October
The weather Porto late September brings leans towards October, when the change is sharp: highs fall to 20.7 °C (69.3 °F) and rain more than doubles to 158.3 mm (6.2 in). For a trip that depends on dry days, early and mid September are the safer part of the month.
Compare August, October and every month on the Porto weather page.
A September plan can still centre on the outdoors, with a little room to move a day. The Douro Valley, the river and the viewpoints all fit, and a tour with free cancellation takes the risk out of a wet forecast. Indoor visits make a good second plan for a showery afternoon.
For clothes, pack for warm days, light layers for the evenings and a compact waterproof. Sun protection is still worth bringing. Compared with October, September is clearly the easier month: highs are about 3.4 degrees warmer and rainfall less than half, so the start of the month is the most reliable part for outdoor plans.
September against the months either side
| Month | Average high | Average low | Rainfall | Sunshine |
|---|---|---|---|---|
| August | 25.7 °C (78.3 °F) | 15.9 °C (60.6 °F) | 32.9 mm | 295 h |
| September | 24.1 °C (75.4 °F) | 14.7 °C (58.5 °F) | 71.9 mm | 224 h |
| October | 20.7 °C (69.3 °F) | 12.2 °C (54.0 °F) | 158.3 mm | 184 h |
- Average high
- 25.7 °C (78.3 °F)
- Average low
- 15.9 °C (60.6 °F)
- Rainfall
- 32.9 mm
- Sunshine
- 295 h
- Average high
- 24.1 °C (75.4 °F)
- Average low
- 14.7 °C (58.5 °F)
- Rainfall
- 71.9 mm
- Sunshine
- 224 h
- Average high
- 20.7 °C (69.3 °F)
- Average low
- 12.2 °C (54.0 °F)
- Rainfall
- 158.3 mm
- Sunshine
- 184 h
Common questions
Is September a good time to visit Porto?
For weather, yes: highs of 24.1 °C and 224 hours of sunshine, with rain starting to return at 71.9 mm.
Does it rain in Porto in September?
More than in summer: 71.9 mm on average, against 32.9 mm in August.
What should I pack for Porto in September?
Light clothes for days around 24 °C, a layer for evenings near 15 °C and a compact waterproof for the wetter days.