September in Barcelona features warm afternoons and evenings with comfortable to cool late nights and mornings.
About 8-9 afternoons will be muggy, however, most are likely to occur early in the month.
Daytime high temperatures tend to be near 26-27 C (79-81 F) early in the month, cooling to about 24-25 C (75-77 F) near the end of the month.
A few of the warmer afternoons, especially early in September, can reach up near 29-30 C (85-86 F).
The record high temperature in Barcelona during September is 33 C (about 91 F).
Late night and early morning low temperatures will tend to be around 18-20 C (65-68 F) early in September, cooling to 16-17 C (61-63 F) near the end of the month.
A few of the cooler mornings, especially later in the month, can dip down near 12 C (54 F).
The record low temperature in Barcelona during September is 7.8 C (46 F).
Sky and Rain
In Barcelona during September, you can expect about 16-17 sunny, 4-5 partly sunny, and about 9 cloudy days.
It is more likely to have a cloudy day late in the month than at the beginning.
Some rain falls on about 10-11 days, however, only 5-6 days will record 1 mm (0.04 inches) or more.
The number of daylight hours decreases rapidly this month from about 13.1 hours on the 1st to 11.8 hours by the 30th.
The wind in Barcelona this month tends to be mostly light to gentle at 6-19 kph/4-12 mph.
Ocean and Beach
September is still a great time for the beach as water temperatures remain relatively warm, mostly 23-24 C (73-76 F).
What to Wear in Barcelona During September?
September features warm afternoons but generally cool to comfortable nights. A mix of spring and summer attire is recommended for this month.
We suggest a light windbreaker, some long-sleeved shirts, and tops for the cooler evenings but light summer attire for the warm afternoons.
Don’t forget sunglasses, sunscreen, and some comfortable walking shoes!
Things to Do in Barcelona in September
There will be several sunny days this month, which makes it an excellent time to think about taking a pay-what-you-wish walking tour in Barcelona.
With cooler weather on the horizon, you might want to think about enjoying one last day at the beach while it's still nice and warm.
If you're looking to get out on the water, there are plenty of different cruises and sailing excursions available in Barcelona with prices starting at just €12.
Once the sun goes down, consider going to see a Flamenco show at one of the many venues that specialize in these performances.
For even more ideas, make sure to read our post covering things to do in Barcelona.