San Francisco · United States
September
San Francisco's best-kept secret — warmest, clearest month, and crowds just starting to thin.
Best match
#2 of 12 months
September is one of the best times to visit San Francisco.
Climate
High
20.8°C
Low
12.8°C
Rain
6mm
Sun
8.8hrs/day
30-year climate normals · Open Meteo ERA5
How September scores in San Francisco
Weather
Outstanding
Value
Above average
Crowds
Above average
Events
Very good
Atmosphere
Outstanding
What you gain in September
- ↑September is unequivocally the best weather month in San Francisco. The fog retreats dramatically — the marine layer that dominates June through August dissipates as the Pacific High weakens and the temperature differential between sea and land reduces. Average highs reach 21°C with abundant sunshine and minimal wind. The "second summer" that Bay Area residents wait for all year begins: clear skies, warm afternoons, and the city finally matching what visitors imagined when they booked. This is the month to spend time at Ocean Beach, Crissy Field, and the outdoor restaurants of the Castro and Mission.
- ↑Post-Labor Day (first Monday of September), the tourist infrastructure immediately eases. Alcatraz is bookable 3–5 days in advance, hotel rates drop 20–30% from August peaks in the fortnight following Labor Day, and the feeling of the city noticeably shifts from tourist operation to local life. This transition is one of the most reliable improvements in any major US city.
- ↑Fleet Week preparations begin in October, but the air show rehearsal flights over the bay that happen in late September are freely visible from the Embarcadero. The Blue Angels practicing formation over the bay bridge is a genuinely thrilling and unexpected spectacle.
What you sacrifice
- ↓September is still peak-adjacent on pricing — the week before Labor Day and during the long weekend itself sees hotel rates at near-August levels. The post-Labor Day drop is significant but doesn't quite reach spring pricing.
- ↓The city's tech conference season begins in September, which means Moscone Center events drive up midweek hotel rates and create localized demand in the SoMa and Union Square areas. Checking the conference calendar before booking dates can save significant money.
How September compares to October (best month)
| Factor | September | October ★ |
|---|---|---|
| Weather | 9 | 9 |
| Value | 5 | 6 |
| Crowds | 5 | 6 |
September in other destinations
Lisbon (24.6°C)Barcelona (25.5°C)Tokyo (28.1°C)Bali (30.4°C)Santorini (24.1°C)Paris (21.6°C)New York (23.9°C)Marrakech (31.6°C)Amsterdam (18.8°C)Maldives (30.2°C)Rome (26.5°C)Bangkok (31°C)Istanbul (24.2°C)Vienna (22.1°C)Seoul (25.1°C)Dubrovnik (24.9°C)Rio de Janeiro (27.3°C)Kyoto (28.6°C)Phuket (31°C)Cape Town (19°C)Prague (21°C)Amalfi Coast (27°C)Mexico City (22°C)Medellín (28°C)Fiji (27°C)London (20°C)Sydney (20°C)Iceland (10°C)Tulum (32°C)Dubai (39°C)Singapore (32°C)Hoi An (31°C)Chiang Mai (31°C)Miami (32.8°C)Florence (26.3°C)Queenstown (12.5°C)Madrid (28.7°C)Porto (25°C)Edinburgh (16°C)Copenhagen (18°C)Budapest (23°C)Kraków (19°C)Tbilisi (26°C)Palawan (30°C)Hanoi (31°C)Osaka (29°C)Goa (30°C)Cusco (20°C)Buenos Aires (18°C)Mykonos (27°C)Zanzibar (27°C)Sri Lanka (30°C)Costa Rica (24°C)Cancun (31°C)Krabi (31°C)Athens (29°C)Seville (31°C)Cartagena (31°C)Siem Reap (31°C)Havana (31°C)Split (26°C)Taipei (31°C)Kuala Lumpur (32°C)Valletta (29°C)Ho Chi Minh City (32°C)Hawaii (31°C)Cappadocia (27°C)Dominican Republic (31°C)Jamaica (32°C)Tanzania (25°C)Seychelles (27°C)Nepal (26°C)Jordan (32°C)Azores (25°C)Bora Bora (27°C)Los Angeles (28.1°C)Cairo (35.9°C)Kenya (25.3°C)Jaipur (32.1°C)Las Vegas (36.2°C)Madeira (26.5°C)Vancouver (19.2°C)Muscat (38.1°C)Lima (17.8°C)Cinque Terre (25°C)Kotor (27°C)Tel Aviv (30°C)Santiago (18°C)Bogotá (18°C)Bruges (19.2°C)Penang (31.8°C)Lombok (31°C)Cape Verde (29.2°C)Fez (32.8°C)Kerala (30°C)Kigali (27°C)Hong Kong (29°C)Oslo (18°C)Auckland (16°C)
Climate data: 30-year normals (1991–2020) from Open Meteo ERA5 reanalysis. Scores compare months within San Francisco, not across destinations. Methodology →