Being able to predict what the weather will be is tricky business, made more difficult when you are trying to figure out what to expect on a trip that is several months away. This is made even harder if that destination is in a place you are not familiar with, like Barcelona. But you can get a fairly accurate idea of what to expect weather-wise from historical average temperatures and precipitation for any given location.
The weather is fairly reliable in the Catalan capital in September. It is usually warm, but not too hot. At nighttime, the temperature drops, but not massively. Rain is rare but possible. Barcelona's streets, parks, and patios are alive during this month when late summer turns toward autumn. And every September, Festes de la Merce, one of Barcelona's biggest festivals, dominates the city for a week.
Barcelona Weather in September
Weather just doesn't get much more perfect than what Barcelona experiences in September. It's sunny nearly every day, with only five days on average with rain. Afternoon highs average 79 F and nighttime lows 65 F. The sea temperature averages 75 F during September, which makes it a good time spend your day on Barcelona's beaches, which are much less crowded than during the summer vacation period. Because fall arrives in September, when temperatures begin to fall throughout the Northern Hemisphere, you should be aware that higher temperatures will predominate at the beginning of the month and fall as you reach the end.
If you want to know more specifically what you are likely to encounter on the exact days you will be there, check out Accuweather's historical daily averages.
What to Pack
Packing for this kind of weather is a snap. It's neither hot nor cold, and it rarely rains. Take long pants, jeans, and capri pants (for women), along with a few short-sleeved shirts or tees, a couple long-sleeved shirts, and a cotton sweater, poncho, pashmina, or lightweight jacket for evening.
As with any European city, you need comfortable walking shoes. In this weather, they can be Birkenstocks, boat shoes, or canvas shoes. They can be open or closed-toe but should be lightweight and breathable. Bring a swimsuit, beach topper, sunscreen, sunglasses, and a hat if that's your style. Barcelona has a big nightlife scene, so if you want to experience that, take clothes that are appropriate: sports jacket and casual pants for men, tie optional; and nice tops and sandals that look the part for women; skirts optional.
September Events in Barcelona
Barcelona's perfect weather in September makes it an ideal time for outdoor events and festivals, and the city takes advantage of it. You'll find free jazz concerts in public squares, an accessible art fair, a wine and cava fest that features Catalan labels, Catalan's national day celebration, and the granddaddy of all the events, the Festes de la Merce, which goes on for a week every September.
Festival L’Hora del Jazz: This jazz festival of local acts covers three weeks in September and features free daytime concerts in public squares.
Catalan National Day: Celebrated every Sept. 11, Catalan National Day commemorates the fall of Barcelona to the Bourbon Army in 1714 during the War of Spanish Succession.
You'll see marches through the city flags flying.
Festes de la Merce: This weeklong annual event honors the patron saint of Barcelona and includes 600 events that include fireworks displays, free concerts, street theater performances, and many activities for children.
Swab Barcelona International Contemporary Art Fair: Emerging artists and galleries are the focus of this art fair, which has a goal of making art accessible to everyone.
September Travel Tips
Traveling to Barcelona entails a bit of risk. There's civil unrest in Catalan, and petty thieves are a serious threat on the streets.
Catalan Day Closures: You might find some restaurants, bars, stores, and museums closed on this day of national celebration.
Catalan Unrest: Currently Catalan and Barcelona are experiencing occasional political unrest related to a movement for independence from Spain. Also, there was a terrorist alert for Spain as of January 2018. You should check the U.S. Department of State website before you go and check in with the State Department at the time you leave, in an abundance of caution.
Pickpockets: Barcelona is known for its abundance of pickpockets, especially in the city center and areas where tourists frequent. In September the streets are crowded, and it is a high-risk time for being the victim of petty thieves.
Know When to Eat: Unlike most of Europe, Spaniards eat lunch at around 2:30 p.m. and dinner no earlier than 9 p.m. Nightlife goes on well after midnight.
Book Restaurants and Tickets: Barcelona is a destination that's in demand, and that results in long lines at museums and restaurants. The smart money is on making reservations or buying tickets well in advance.
If you'd like to know more about the best time to plan a trip to Barcelona, have a look at this guide.