Best Time to Visit San Francisco: When to Go and When to Skip

The best time to visit San Francisco is September to October. The fog that characterises the city in summer (locals call it Karl) retreats, temperatures reach their annual warmest (around 18-22C), and the skies are clear. This surprises many visitors who assume summer is the obvious choice. San Francisco's micro-climates mean the timing matters more than in most cities.

Month-by-Month Breakdown

• January to February: Mild but wet (around 10-13C). Rain is more frequent in winter than at any other time. The city is quiet and hotel prices are lower. Indoor attractions, the Ferry Building market, and the museums are well-suited to rainy-day visits.
• March to April: Improving conditions. Temperatures around 12-15C. Rain reduces. A solid spring window before the summer fog season begins.
• May: Warming but the fog season starts building. May can be overcast across much of the city, particularly in the morning.
• June to August: San Francisco's infamous summer fog peaks in June and July. The city averages around 17-19C but the marine layer keeps skies grey over Fisherman's Wharf and the waterfront for hours every morning. Golden Gate Bridge disappears entirely on many days. The city is still very enjoyable but the "summer holiday" expectation of sunshine often disappoints.
• September: The fog retreats and the warmest, clearest weather of the year arrives. Around 18-22C, blue skies, and the Bay at its most photogenic. One of the best months in the city.
• October: Still excellent. Clear and warm (16-20C). The bay views are at their best and the city is in good form.
• November: The weather shifts. Rain returns and temperatures drop toward 12-14C. Still comfortable compared to most of the US in November.
• December: Mild (around 10-13C) and can be rainy. The festive period adds activity around Union Square. Not a bad winter city break option if the weather is accepted.

Peak Season

Summer (June to August) sees the highest visitor numbers despite the fog, largely driven by school holidays and US domestic travel. Hotels near Fisherman's Wharf and Union Square are at their most expensive. Alcatraz ferry tickets sell out weeks ahead.

Shoulder Season

September and October are the practical sweet spots. The best weather, manageable crowds, and prices that are lower than the summer peak. These months are when San Francisco finally gives visitors the postcard version of itself.

What to Avoid

Expecting summer sunshine in June and July without researching the fog. Many visitors arrive in July in short sleeves expecting California warmth and find 16C and overcast mornings. Pack layers regardless of the month; San Francisco's micro-climates can swing 8-10 degrees between the Mission District and the waterfront.

For everything you need to plan your trip around the timing, our San Francisco city break guide covers it.