Spain Barcelona Weather in September — Climate Guide
September in Barcelona is Excellent
September is Excellent for Barcelona.
**September is Barcelona's perfect month** — 26°C/18°C, sea still 23°C, crowds drop slightly, prices begin dropping. **La Mercè** (September 24, week of festivities) is the city's biggest festival: castellers (human towers), correfocs (fire runs), giant puppet parade, free concerts. Diada Nacional (September 11) is the Catalan National Day with independence rallies.
Travel score
Barcelona September Weather Stats
Avg High
26°C
Avg Low
18°C
Rainy Days
5
60mm total
Sunshine
7.5h
Daily avg
Humidity
71%
Comfortable
UV Index
6
High
Wind
11 km/h
Gusts 22
Sea Temp
23°C
Avg water temp
Crowds
Busy
At attractions
September Sunrise & Sunset
Air Quality
PM2.5
22 μg/m³
PM10
33 μg/m³
Status
Moderate
Feels-Like Temperature & Wind
Feels like
Daytime
26°C
Nighttime
18°C
Humidity and wind affect how the actual temperature feels.
Wind
11 km/h
Max gust 22 km/h
Activities Recommended for September
September Travel Pros & Cons
Pros
- Best month overall — perfect weather + manageable crowds
- La Mercè biggest festival
- Sea still 23°C swimmable
- Hotel prices begin dropping after first week
Cons
- First week still summer peak
- Diada protests can disrupt routes
- Some restaurants still on August schedules
September Events & Festivals
- La Mercè Festival (Sept 24, biggest of the year)
- Diada Nacional (Sept 11, Catalan National Day)
- Castellers performances
Barcelona in September — Full Picture
**September is Barcelona's perfect month** — 26°C/18°C, sea still 23°C, crowds drop slightly, prices begin dropping. **La Mercè** (September 24, week of festivities) is the city's biggest festival: castellers (human towers), correfocs (fire runs), giant puppet parade, free concerts. Diada Nacional (September 11) is the Catalan National Day with independence rallies.
What to Wear & What to Pack
Warm — t-shirts + sundresses still work. Add a sweater for evenings (drops to 18°C). Light rain jacket for occasional September showers.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
18.7°C
10°C
5.7/mo
Summer (Jun·Jul·Aug)
28°C
19.3°C
3.7/mo
Autumn (Sep·Oct·Nov)
Current21.7°C
13.7°C
5.3/mo
Winter (Dec·Jan·Feb)
14.3°C
5.7°C
5/mo
Barcelona Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| 14° | 5° | 5d·41mm | 5h | 70% | 2 | Quiet | Low season | |
| 15° | 6° | 5d·39mm | 6h | 70% | 3 | Quiet | Low season | |
| 16° | 8° | 5d·36mm | 6h | 69% | 4 | Moderate | Shoulder | |
| 18° | 9° | 6d·47mm | 7h | 70% | 5 | Moderate | Peak | |
| May (Best) | 22° | 13° | 6d·47mm | 8h | 71% | 7 | Busy | Peak |
| June (Best) | 26° | 17° | 4d·30mm | 9.5h | 70% | 9 | Busy | Peak |
| 29° | 20° | 3d·21mm | 10.5h | 70% | 9 | Very busy | Peak | |
| 29° | 21° | 4d·49mm | 9h | 71% | 8 | Very busy | Peak | |
| September (Best) | 26° | 18° | 5d·60mm | 7.5h | 71% | 6 | Busy | Peak |
| 22° | 14° | 6d·87mm | 6h | 72% | 4 | Moderate | Shoulder | |
| 17° | 9° | 5d·53mm | 5h | 72% | 2 | Quiet | Low season | |
| 14° | 6° | 5d·41mm | 4.5h | 71% | 1 | Busy | Peak |
View Other Months
Barcelona September Hotel Picks
Frequently Asked Questions
Is September a good time to visit Barcelona?
Barcelona in September is Excellent. Tourist crowds are busy and flight/hotel prices are peak.
What's the average temperature in Barcelona in September?
Barcelona September averages a high of 26°C and a low of 18°C.
Does it rain much in Barcelona in September?
Barcelona September averages 60mm of rainfall over about 5 rainy days.
What should I wear in Barcelona in September?
Warm — t-shirts + sundresses still work. Add a sweater for evenings (drops to 18°C). Light rain jacket for occasional September showers.
What time are sunrise and sunset in Barcelona in September?
Barcelona September sunrise is 07:25 and sunset is 20:00, with 12h 35m of daylight.
What's the air quality like in Barcelona in September?
Barcelona September air quality (AQI) averages 50, rated Good. PM2.5 averages 22μg/m³.
What activities are recommended in Barcelona in September?
In September, Barcelona is great for La Mercè festival (Sept 24), Castellers human towers, Correfocs fire run.
Is September peak season in Barcelona?
Barcelona September crowds are busy and prices are peak. Advance reservations are strongly recommended.
Best Months to Visit Barcelona
View Other Months
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.