San Francisco Weather by Month: Temperatures, Rain and What to Pack

September and October are the warmest months in San Francisco and also two of the driest, which makes them the safe pick. The 1991 to 2020 normals from NOAA, the US weather agency, put the average high at 70.2°F (21.2°C) in September and 69.8°F (21.0°C) in October. Summer is cooler than most visitors expect, with July at 66.3°F (19.1°C), and the rain comes in winter. December is the wettest month at 4.76 in (120.9 mm) and July the driest at 0.01 in (0.3 mm).

The range is narrow. The average high never goes above 70.2°F or below 57.8°F in any month, so the question for a trip is less how hot it will be than how wet, and what you’ll need to carry for the evenings.

San Francisco weather by month

The figures are NOAA’s National Centers for Environmental Information 1991 to 2020 U.S. Climate Normals for the San Francisco Downtown station (monthly normals file). The source gives °F and inches, and the metric figures are converted from them. Rainy days are days with 0.01 in (0.25 mm) or more of precipitation.

This is one station in the middle of the city, a few kilometres from the bay. NOAA’s file for San Francisco International Airport (here) reads a few degrees warmer in the same months, with a September high of 74.8°F against 70.2°F downtown. Two places in one city can differ by that much, so treat any single figure as a guide and not a promise. These are also averages, and a single week can run well either side.

September and October: the warm, dry months

September has the highest average high of the year at 70.2°F, a 55.6°F low and only 0.10 in of rain over 1.2 days. October is nearly as warm at 69.8°F and 54.4°F, with 0.94 in over 3.5 days, so the first wet days of the season can turn up late in the month. These are the months when you’re most likely to get a clear afternoon at the Golden Gate Bridge and a dry walk along Lands End.

Evenings still cool to the mid 50s°F, so you’ll want a jacket once the sun goes down. The September events page and the October events page list what’s on.

June, July and August: cool, not hot

Highs run from 66.3°F in July to 67.9°F in August, with lows of 53.0°F to 55.5°F. Most visitors planning a California trip expect beach weather in these months, and the normals say otherwise. A light jacket or a sweater is the usual answer for an evening, and the figures are close enough to those of April and May that you shouldn’t leave the warm layers at home.

What these months do have is almost no rain. June averages 0.20 in over 1.6 days, July 0.01 in over 0.7 days and August 0.06 in over 1.1 days. NOAA’s July figure is the lowest of any month in the table, at 0.3 mm. Outdoor plans rarely need a wet-weather backup, which suits the open-air events. Outside Lands is listed for 6 to 8 August 2027 in Golden Gate Park, so the August events page is worth a look if you’re planning around it. The June events page and the July events page cover the rest of the summer.

March, April and May: spring

Spring is the transition from wet to dry. March still has 3.15 in over 10.8 days, close to January’s count, but April drops to 1.60 in over 6.8 days and May to 0.70 in over 4.0 days. Highs climb from 62.1°F to 64.1°F across the three months, and lows from 48.9°F to 51.4°F.

April and May are the middle ground in the table. You get low rain totals, most of the day mild, and cool nights. Bay to Breakers is listed for 16 May 2027, so the May events page is the one to open if you’re travelling then. The March events page and the April events page list the rest.

November to February: the rainy season

The rain returns in November, which averages 2.60 in over 7.9 days with a 63.7°F high. From December to February the totals run from 4.37 in to 4.76 in a month, and rain falls on about 11 days in each (11.6 in December, 11.2 in January, 10.8 in February). Highs hover around 58°F to 60°F and lows sit in the 46.6°F to 47.9°F range.

San Francisco’s winters are mild, with none of the freezing nights that cold-climate cities see. The thing to plan for is rain rather than cold, so a waterproof jacket does more than a heavy coat, with a sweater underneath. Wet days are best spent on the indoor side of the city, and the California Academy of Sciences is one of the places in the places list that works in any weather. Check the November events page, the December events page, the January events page and the February events page for what’s on.

Which month has the best weather?

September and October, when the high is close to 70°F and the rain is at its lowest. If you can’t travel then, late spring is the next best window, with May at 64.1°F and 0.70 in. Summer is dry but cool, and winter is mild but wet, so neither is a bad choice if the dates suit you better.

What to pack

• A light jacket or fleece for every month, since the lowest average high of the year is 57.8°F and evenings never stay warm.
• A waterproof jacket from November to March, when 7.9 to 11.6 days a month see rain.
• Comfortable walking shoes, because getting around usually means hills and a lot of stairs.
• A sweater or scarf for the evening, even in September, when the average low is 55.6°F.

Planning around the weather

• Use the map to find indoor places for wet days, and events for what’s on the dates you travel.
• The things to do guide groups the main sights by area, which makes it easier to swap an outdoor plan for an indoor one.
• The day trips guide is best saved for a dry month.

Places in this guide

Photos show the actual places, licensed under Creative Commons and credited to their photographers.

Lands End Richmond District and Lands End Photo: Sharon Mollerus