San Francisco Weather
San Francisco's weather is as changeable as the seas, literally. Surrounded on all sides (save one) by ocean and bay, San Francisco's weather is also one of the hardest to forecast and changes drastically from neighborhood to neighborhood. Over four seasons, not one of which corresponds to its climatic expectations, San Francisco's weather can be difficult for visitors to predict, save that Fog City delivers majestic skies, trademark plumes of white fog and brilliant sunsets.
The Four Seasons
Spring in San Francisco
March, April and May are some of the most inviting months to visit San Francisco. Characteristically cloudless and mild, some of the warmest and driest days of the year occur in San Francisco's spring months, making San Francisco's springtime noticeably free from the spring showers that moisten other parts of the United States.
Summer in San Francisco
San Francisco summers have scant in common with summers elsewhere. Marked by billowing white fog, the majestic product of sea spray, wind and Central Valley heat, San Francisco summers are characteristically overcast and cool, while the marine layer usually burns off by the afternoon. By late August, however, the fog thins and produces the iconic white finger of white pouring through the Golden Gate Bridge, rolling over Treasure Island and splaying against the Berkeley and Oakland hills, missing much of San Francisco altogether.
Fall in San Francisco
Fall in San Francisco is truly the best time of year for weather. Days are warm and sunny, sometimes blisteringly so, and nights are mild and clear. Rainfall is rare, the fog has cleared and the long warming process has reached its magnificent zenith, making September, October and early November the three best months to visit San Francisco.
Winter in San Francisco
In February, 1887, four unexpected inches of snow fell on downtown San Francisco. An exception that occurred once in 1976 and hasn't since, snow in San Francisco is rare, even in San Francisco's coldest months of the year, December and January. Rain, on the other hand, is abundant and storms from the moist coasts of Mexico and Central America bring anything from light showers to torrential downpours from December through February. On the whole, San Francisco winters are mild compared to the rest of the country, and days between storms can be surprisingly crisp and sunny.
The Best Times to Visit San Francisco
While June, July and August typify summer in most of the Northern hemisphere, San Francisco (as in many areas) does not conform to expectations.
With an annual "Indian Summer," September to November is the best time to visit San Francisco. Daily temperatures are at their highest across the peninsula, usually in the mid to high 60s, but often reaching into the 80s and 90s, and make for a sweltering downtown and a jam-packed Golden Gate Park. A smooth, glassy bay and hot blasts from the Central Valley combine to make fall temperatures in San Francisco the best. During these months, Ocean Beach and Baker Beach are dotted with bikini-clad San Franciscans slathered in oil and soaking the sun like Los Angelians. Nights are warm and lend to summer dresses and short-sleeved shirts, while the sky is clear and stars are bright.
What to Pack
Layers, layers, layers. Even in the warmest months, San Francisco visitors should always bring a light jacket. Unexpected upswells from the deep and frosty Pacific Ocean and chilling blasts sweep over San Francisco without notice and can change San Francisco's weather in an instant. Overall, jeans, light sweaters, long sleeve shirts and close-toed shoes make up the typical San Franciscan's wardrobe, with the occasional voyeur daring a short skirt (pared with a heavy jacket) and sandals in the "summer" months.