Best Time to Visit San Francisco: Fog, Rain and Events

When is the best time to visit San Francisco?

September and October are the best months to visit San Francisco for most people. They are the warmest months downtown, the summer fog eases and little rain falls. Late April to early June is the next best window. Midsummer is cool and foggy rather than hot, and November to March brings most of the rain.

San Francisco turns the usual seasons upside down. NOAA’s 1991–2020 normals for the downtown station put the warmest month in September, with an average high of 21.2°C (70.2°F), while July averages 19.1°C (NOAA NCEI). The whole year spans only about 7°C between January’s and September’s average highs, so the real choice is between fog, sun and rain rather than heat and cold.

This guide uses the NCEI downtown normals for every weather figure, San Francisco Travel for fog and neighbourhood guidance, and organisers’ own sites for event dates, all checked on 16 October 2026. Where a 2027 date had not been published, we give the 2026 date as a guide and say so.

Once you have a month, pick a base with where to stay in San Francisco, pace the trip with the San Francisco 3-day itinerary, and check entry paperwork in ESTA for UK travellers.

Is summer a good time to visit San Francisco?

Only if you pack for fog. San Francisco Travel calls June to August prime fog season, with fog often rolling in before sunset on the west side and at the coast, and downtown July averages a high of just 19°C. Summer days are long and almost rain-free, so it still suits travellers who layer up.

San Francisco Travel’s sunset guide describes summer (June to August) as prime “Karl the Fog” season and autumn (September to October) as the time of the clearest, warmest evenings. Its packing advice says morning and evening fog rolls in during summer but rarely persists, and that temperatures seldom rise above 21°C (70°F) or fall below 5°C (40°F).

For sightseeing, fog changes the order of your day rather than ruling anything out. The tourism board’s advice for the Golden Gate Bridge is to plan your crossing before the late afternoon, when the fog tends to roll in (San Francisco Travel). The National Park Service warns Alcatraz visitors that cold, foggy mornings can turn sunny and then foggy and windy again (NPS).

The practical answer is layers. A light windproof jacket over a jumper covers most summer days, and you will be glad of it on the Alcatraz ferry or at Lands End. Travellers who pack only for California sunshine are the ones caught out.

What is San Francisco’s weather like month by month?

Downtown San Francisco barely changes temperature through the year: average highs run from 14°C in January to 21°C in September, according to NOAA’s 1991–2020 normals. Rain is the real seasonal divide. December, January and February each average more than 110mm, while June to September together average under 10mm.

The table converts the NOAA NCEI monthly normals for San Francisco Downtown into Celsius and millimetres. Wet days are days with at least 0.25mm (0.01in) of rain. The station is well inland of the ocean beaches, and San Francisco Travel says the fog tends to settle over the Richmond and the Sunset (San Francisco Travel), so expect greyer days there than these figures suggest.

Annual rainfall averages about 581mm (22.9in), and roughly 84% of it falls between November and March. July is effectively dry, averaging 0.7 wet days. Hot days are rare but real: highs of 32°C (90°F) or more average 1.3 days in September and 0.9 in October, so an autumn trip can need both a jacket and sun cream.

Nights stay mild all year: the coldest month, January, still averages a low of 8.1°C. That makes San Francisco a reasonable winter city break, as long as you accept rain on roughly one day in three from December to February.

Which parts of San Francisco are foggiest, and where is it clearer?

The Richmond and Sunset districts by the ocean get the most fog, according to San Francisco Travel, and Bayview is the city’s sunniest neighbourhood. For visitors, that means saving Lands End and Ocean Beach for clear days and doing summer sunsets from higher, more inland spots such as Twin Peaks.

San Francisco Travel’s neighbourhood guide says the famous fog tends to hang over the Richmond and the Sunset, while Bayview is the sunniest district. Its packing page adds that the weather can change by the hour and within a few blocks, which is why locals carry a layer even on bright mornings.

For sunsets in July, the tourism board suggests choosing an inland or elevated viewpoint such as Twin Peaks or Grand View Park over the beach (San Francisco Travel). In September and October, the west-side beaches and Lands End come into their own, because the evening fog is less reliable.

Use this when you choose a base. Downtown, SoMa and the Mission sit on the bay side of the hills, while the ocean districts are a long Muni ride from most sights. Our where to stay in San Francisco guide compares the bay-side neighbourhoods.

How wet is San Francisco’s rainy season?

Wet enough to shape a winter trip but rarely enough to cancel one. December is the wettest month downtown at about 121mm over roughly 12 rainy days, and November to March delivers most of the year’s rain. Mild temperatures mean winter still works for museums, food halls and neighbourhood walks between showers.

From December to February, the NCEI downtown normals average between 10.8 and 11.6 wet days a month, with average lows above 8°C. Even in December, about 19 of 31 days stay dry on average, so plan outdoor sights for the dry spells and keep indoor options ready.

Indoor anchors are strong. SFMOMA opens six days a week and closes on Wednesdays, and the California Academy of Sciences in Golden Gate Park opens from 9:30am to 5pm Monday to Saturday and from 11am on Sundays. The Ferry Building market runs year round on Tuesdays, Thursdays and Saturdays (Foodwise).

Winter also brings the holiday closures: Alcatraz is closed on Thanksgiving, Christmas Day and New Year’s Day, and SFMOMA closes on Thanksgiving and Christmas. Fit the island around those dates if you are travelling over the festive period.

Which San Francisco events in 2026–27 affect crowds and hotel prices?

The coming year’s big dates are the Chinese New Year Parade on 20 February 2027, Bay to Breakers on 16 May, Pride on 26–27 June and Outside Lands on 6–8 August. October brings Fleet Week and Hardly Strictly Bluegrass; their 2027 dates were not yet published when we checked.

Dates come from the organisers: the Chinese New Year Parade (20 February 2027, the Year of the Ram), Bay to Breakers (16 May 2027), San Francisco Pride (26–27 June 2027, its 57th celebration) and Outside Lands (6–8 August 2027). Outside Lands is held in Golden Gate Park (San Francisco Travel).

October is packed with events. In 2026, San Francisco Travel listed Hardly Strictly Bluegrass in Golden Gate Park on 2–4 October, Fleet Week from 4 to 12 October and the Italian Heritage Parade in North Beach on 11 October. Expect October 2027 to follow a similar pattern, which adds crowds to the best-weather month.

Each event concentrates people in one area: Pride downtown; Fleet Week’s air show over the bay, watched from Crissy Field, Marina Green, Aquatic Park and Pier 39 (San Francisco Travel); and Outside Lands and Hardly Strictly in Golden Gate Park. If your dates overlap, stay away from the affected district or book early.

How do conventions and US holidays affect a San Francisco trip?

Large Moscone Center conventions compete with visitors for SoMa and Union Square rooms, so check the venue calendar before booking. US holidays matter mainly for sights: Alcatraz closes on Thanksgiving, Christmas Day and New Year’s Day. Thanksgiving falls on 26 November 2026 and Memorial Day on 31 May 2027.

The Moscone Center events calendar lists conventions and trade shows at the city’s main venue in SoMa. If a big conference overlaps your dates, consider North Beach, the Mission or Fisherman’s Wharf instead of the streets around Yerba Buena.

Hotel taxes are the same whenever you go: San Francisco charges a 14% transient occupancy tax on stays under 30 days, and hotels in the Tourism Improvement District add an assessment of 2.25% or 2% depending on zone, which they may list separately (San Francisco Treasurer). Compare totals, not nightly rates.

For holiday dates, the Office of Personnel Management lists Thanksgiving on 26 November 2026, Christmas Day on Friday 25 December, Memorial Day on 31 May 2027, Independence Day observed on Monday 5 July 2027 and Labor Day on 6 September 2027. Alcatraz Night Tours do not run on Christmas Eve, New Year’s Eve or 4 July (Alcatraz City Cruises).

Do wildfire smoke and earthquakes affect when to visit?

They are risks to monitor rather than reasons to avoid a season. The National Park Service notes that ozone and wildfire smoke can reduce visibility around Alcatraz in summer and autumn, and the UK government lists California among US areas at higher earthquake risk. Check air quality before outdoor days.

The NPS Alcatraz conditions page says winter inversions can trap smog and that summer and autumn ozone and wildfire smoke can reduce visibility and affect sensitive people. Because September and October are also the best-weather months, travellers who are sensitive to smoke should keep plans flexible in those weeks.

The UK government’s USA travel advice says earthquakes can happen anywhere in the US without warning and names California among higher-risk areas. It points travellers to CAL FIRE for wildfire information and advises following evacuation orders and local instructions. Learn the “drop, cover and hold on” routine and check your hotel’s emergency information on arrival.

None of this changes the core advice for most trips. If smoke appears in the forecast, switch outdoor days for museums, ride the ferry another day, and use refundable bookings so you can move dates if needed.

Which months suit which kind of San Francisco trip?

First-timers and photographers should aim for September or October. Budget-minded winter travellers can make December to February work with indoor backup plans. Spring suits walkers who want mild, mostly dry days before fog season, and summer suits travellers who do not mind fog and want long days for trips beyond the city.

Families on UK school holidays will usually travel in July or August, which is fine as long as everyone packs fleeces and you plan beaches as walks rather than swims. Festival fans should target Outside Lands (6–8 August 2027) or Pride (26–27 June 2027). Runners can enter Bay to Breakers on 16 May 2027.

For Alcatraz, timing matters less than booking: tours frequently sell out a week or more in advance in any season (Alcatraz City Cruises). Read is Alcatraz worth it before deciding whether the island deserves a half-day of your trip.

• Clearest skies and warmest days: September and October
• Mild, mostly dry shoulder: late April to early June
• Festivals: Pride in June, Outside Lands in August, Fleet Week in October
• Wettest weeks: December to February
• Foggiest weeks: June to August, especially on the west side

How far ahead should you book a San Francisco trip?

Book Alcatraz as soon as dates are fixed if it matters to you, because tours often sell out a week or more ahead. Then lock flights and a cancellable hotel, earlier if your dates overlap Pride, Outside Lands, Fleet Week or a large Moscone convention. Leave museums and cable cars flexible.

Alcatraz access is only via the National Park Service’s contracted ferry from Pier 33 (NPS), and same-day tickets are rarely available (Alcatraz City Cruises). Tour marketplaces also sell packages that include island tickets; whichever route you choose, check that the product lands on the island.

For flights, SFO connects to downtown by BART in about 30 minutes (BART). Compare SFO with Oakland and San Jose for your dates using cheap flights from San Francisco, and plan the airport leg with SFO to San Francisco by BART or transfer.

Keep the hotel refundable until flights are ticketed. If an October conference or festival appears on your dates after booking, moving a week can be the difference between a busy SoMa week and a calm one.

So when should you go to San Francisco?

Go in September or October if you can: the warmest, clearest weeks of the year, with the bridge and coast at their best. Late April to early June is a close second. Summer works if you pack for fog, and winter suits city-break travellers who put museums and food first and do not mind rain.

The single biggest mistake is packing for California sunshine in July. San Francisco’s summer is cool and grey on the coast, while its best beach-and-bridge weather arrives in autumn. Build your plan around that and almost any month can work.

Next steps: choose a base in where to stay in San Francisco, see what earns your time in things to do in San Francisco, and decide on the cable cars with is the San Francisco cable car worth it. The San Francisco destination hub collects the rest.