Question 1

When is the best weather in San Francisco?

Accepted Answer

San Francisco experiences its best weather during September and October, when the city enjoys its warmest temperatures and driest conditions of the year.

Based on 2024 weather data, the September-October period offered an average temperature of 16.1°C (61.1°F) with remarkably low precipitation of just 2.7mm (0.11 inches) combined. October 2024 was the warmest month overall, with mean temperatures reaching 16.6°C (61.9°F) and highs up to 36.2°C (97.2°F). September recorded the driest conditions of the entire year with only 0.5mm of rainfall.

This late-season warmth is characteristic of San Francisco's famous "Indian summer." While traditional summer months (June through August) bring cooler average temperatures of 15.4°C (59.7°F) due to the city's notorious fog, autumn offers clearer skies and more comfortable warmth. June 2024 recorded the most sunshine hours at 349 hours, but average temperatures remained mild at 14.6°C (58.3°F).

For visitors planning a trip to San Francisco, the dry season from June through October is ideal, with total precipitation of just 7.6mm (0.30 inches) across these five months. However, those seeking the warmest and most stable weather conditions should target September and October, when San Francisco delivers sunny skies, comfortable temperatures, and minimal chance of rain.

Question 2

What is the driest month in San Francisco?

Accepted Answer

September is the driest month in San Francisco, with just 0.5mm (0.02 inches) of precipitation recorded in 2024. This makes it the ideal time for outdoor activities and sightseeing without worrying about rain.

The dry season in San Francisco extends from June through October, during which the city received only 7.6mm (0.30 inches) of total rainfall in 2024. September stands out as the driest, followed closely by July with 0.6mm and June with 1.7mm of precipitation. During this period, average temperatures remain pleasant at 15.7°C (60.3°F), offering comfortable conditions for exploring the city.

This dry weather pattern contrasts sharply with San Francisco's wet season. January 2024 was the wettest month, recording 159.8mm (6.29 inches) of rain—over 300 times more than September. The four wettest months (January, February, November, and December) accounted for 479.7mm of the city's total annual precipitation of 623.1mm.

For visitors planning a trip to San Francisco, September offers the best combination of dry weather and mild temperatures. The lack of rainfall during this month means fewer foggy mornings and more opportunities to enjoy the city's famous outdoor attractions, from Golden Gate Park to the waterfront.

Question 3

How foggy is San Francisco in summer?

Accepted Answer

San Francisco is quite foggy during summer, with humidity levels averaging 80.4% from June through August 2024 and a notable decrease in sunshine hours as the season progresses.

The city's famous marine fog, often nicknamed "Karl," is most prevalent in late summer. In 2024, August recorded the highest humidity at 84.0% with only 219.2 sunshine hours—the lowest of any summer month. July followed at 81.2% humidity with 259.6 sunshine hours, while June was the clearest summer month at 76.1% humidity and 349.3 sunshine hours.

This fog pattern keeps San Francisco remarkably cool compared to other California cities. Summer 2024 saw average temperatures of just 15.4°C (59.7°F), with typical highs reaching only 25.9°C (78.6°F). The cooling effect becomes evident when comparing to autumn: September and October averaged highs of 34.5°C (94.2°F), making early fall actually warmer than summer in San Francisco.

For visitors planning outdoor activities, June typically offers the best conditions with more sunshine and lower humidity. The fog usually burns off by late morning, so scheduling outdoor plans for afternoon hours can help avoid the densest morning fog. Bringing layers is essential, as temperatures can swing dramatically between foggy and sunny periods throughout a single day in San Francisco.

Question 4

What is the weather like in San Francisco in October?

Accepted Answer

San Francisco experiences mild and pleasant weather in October, with average temperatures around 16.6°C (61.9°F) and minimal rainfall, making it one of the best months to visit the city.

In October 2024, San Francisco saw daily highs averaging 22.1°C (71.7°F) while nighttime lows dropped to around 12.4°C (54.3°F). Early October brought the warmest conditions, with temperatures reaching up to 36.2°C (97.2°F) on October 1st. The month featured seven days with highs above 25°C (77°F) and five days exceeding 30°C (86°F), offering plenty of warm, comfortable afternoons.

October is notably dry in San Francisco. The city recorded just 2.3mm (0.09 inches) of precipitation across only five days with measurable rainfall in 2024. With 273.5 hours of sunshine throughout the month and an average of 8.8 hours of daily sunshine, visitors can expect mostly clear skies and excellent conditions for outdoor activities.

Humidity averaged 72.9% during October 2024 in San Francisco, though levels varied considerably between foggy mornings and clear afternoons. The combination of mild temperatures, dry conditions, and ample sunshine makes October an ideal time for exploring iconic landmarks like the Golden Gate Bridge, hiking in the Marin Headlands, or enjoying the city's outdoor dining scene.

Question 5

How cold did San Francisco get in winter 2023/24?

Accepted Answer

San Francisco experienced mild winter temperatures during Winter 2023/24 (December 2023 to February 2024), with the coldest overnight low reaching just 4.6°C (40.3°F) on February 8, 2024.

Throughout the winter season, San Francisco maintained comfortable conditions compared to most U.S. cities. The average daily temperature was 11.1°C (52.0°F), with typical lows around 8.4°C (47.1°F) and highs near 14.4°C (58.0°F). Only 4 days recorded minimum temperatures below 5°C (41°F), highlighting the city's famously temperate climate.

The coldest stretch occurred in early January 2024, when temperatures dipped to their lowest averages. January 7, 2024 recorded the coldest daily average at 7.9°C (46.2°F). Despite these cooler periods, San Francisco also saw surprisingly warm winter days, with February 24, 2024 reaching a high of 20.0°C (68.0°F).

Winter 2023/24 brought significant rainfall to San Francisco, with 408.2mm (16.1 inches) of precipitation over 53 rainy days. This wet weather pattern meant residents experienced frequent rain but rarely freezing conditions. For visitors planning a winter trip, layering is recommended as temperatures can vary throughout the day, though heavy winter gear is typically unnecessary in San Francisco's Mediterranean climate.

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FAQ

When is the best weather in San Francisco?

What is the driest month in San Francisco?

How foggy is San Francisco in summer?

What is the weather like in San Francisco in October?

How cold did San Francisco get in winter 2023/24?