yearsofweather

Porto in September:
warm, rain here and there

Porto, Portugal · Records from 2006 to 2025. Not a forecast.

Mean high25°Hottest day 34.9° (2020)
Mean low15°Coldest night 8.1° (2024)
Rain days6 days1-15 by year
Rainfall67mmDaylight 13.1 → 11.8 h
Porto's 12 months iBest: June to August
Trip types Beach Poorcool seaSightseeing on foot Goodmild
Sea temperature17.3°15-19.2° by year (last 6)
Sunrise / sunset (15th)07:14 / 19:45Daylight 13.1 → 11.8 h

Porto in September

The dry summer weather is winding down. Days are often sunny but rainy days increase noticeably. Summer crowds thin out and the city feels more relaxed. Leave some slack in Douro winery tours in case the weather turns.

Daytime highs averaged 25°C, with nights at 15°C. Comfortably warm without being punishing. Out of 30 days, about 6 brought rain; the rest stayed dry. It varied a lot from year to year. September 2009 had 1 rain day; 2014 had 15.

Highs passed 30°C on 2 days on average. Not every year was typical: 2013 ran 2.0°C warmer than the mean, with highs of 26.6°C.

Hurricanes i

1 of the last 20 years had a tropical storm pass within 300 km this month.

  • Alpha (2020), 98 km away tropical storm
1 2 3 4 5 6 7 8 19 10 11 12

Date by date i

‹ August September 2027 October ›
Sun
Mon
Tue
Wed
Thu
Fri
Sat
Week
1-4rain on 15% of days26° 16°
5-11rain on 20% of days26° 16°
12-18rain on 21% of days25° 15°
19-25rain on 25% of days24° 14°
26-30rain on 14% of days23° 14°

0-5/206-8/209-11/2012-20/20

1-4rain on 15% of days26° 16°
5-11rain on 20% of days26° 16°
12-18rain on 21% of days25° 15°
19-25rain on 25% of days24° 14°
26-30rain on 14% of days23° 14°
Tap another date to change

200613mm
2007none
2008none
2009none
20101mm
2011none
20122mm
2013none
2014none
2015none
20164mm
20171mm
2018none
20195mm
2020none
20215mm
2022none
2023none
202421mm
2025none
Holidays in September (2027)
  • September 6 Labor Day

1 US holidays (flights fill up)

Day by day temperature i

13°21°28°36° 1815222930

Mean high Mean low Coldest to warmest high in 20 years

Your trip dates, the past 20 years

Trip dates ~

You can also click two dates on the axis. Hover a cell to see that day's rain.
Trip rain days Month rain days
2006
0 d 8 d
2007
0 d 3 d
2008
2 d 6 d
2009
0 d 1 d
2010
3 d 5 d
2011
1 d 4 d
2012
0 d 4 d
2013
0 d 5 d
2014
4 d 15 d
2015
0 d 4 d
2016
0 d 4 d
2017
0 d 1 d
2018
1 d 2 d
2019
0 d 4 d
2020
0 d 6 d
2021
3 d 10 d
2022
5 d 11 d
2023
5 d 14 d
2024
1 d 5 d
2025
3 d 7 d
Years with rain
Tap a date to start, tap another to end. Each cell is that date in one year.
'06'07'08'09'10'11'12'13'14'15'16'17'18'19'20'21'22'23'24'25
of 20
2
2
3
5
4
3
6
4
4
4
3
1
6
4
6
4
5
4
3
4
4
6
6
8
4
1
2
4
4
3
Rain days on trip
00203100400010035513

No rain1-9 mm10 mm or more Dates outside your trip are dimmed.

One row per year, one cell per day. 2009 had 1 rain day, 2014 had 15.

Porto through the year

MonthHighLowRain daysRainfallSea
January 14°7°12 days148mm 14°
February 16°7°11 days118mm 14°
March 17°9°11 days110mm 14°
April 19°11°10 days100mm 15°
May 21°12°8 days69mm 16°
JuneGood 23°15°6 days39mm 17°
JulyGood 26°16°2 days12mm 17°
AugustGood 26°16°2 days11mm 17°
September 25°15°6 days67mm 17°
October 22°14°11 days142mm 17°
November 17°10°13 days172mm 17°
December 15°8°13 days144mm 15°

Common questions

Does it rain a lot in Porto in September?

Over the past 20 years September averaged 6 rain days (1 mm or more) out of 30. Individual years ran from 1 in the driest to 15 in the wettest.

What should I wear in Porto in September?

Days averaged 25°C and nights 15°C. Pack a compact umbrella, a light layer for the evenings, T-shirts, and sunscreen plus a hat.

Can you swim in Porto in September?

Sea surface temperature averaged 17.3°C in September, too cold for most people without a wetsuit. Year to year it ranged 15-19.2°C. Check local flags for waves and jellyfish on the day.

Is September a good time to visit Porto?

On warmth and rain days alone, Porto's easiest months were June to August. September ranked 4 of 12.