San Francisco Faces Coldest Summer in Over Three Decades

San Francisco is experiencing its coldest summer in over three decades, with average daily temperatures hovering around 59°F. This unseasonably cool weather is attributed to a persistent low-pressure system off the California coast, which has been blocking warmer air from entering the region. The National Weather Service notes that July 2025 may rank among the coldest 10% of Julys on record.

While San Francisco is known for its cool, foggy summers, the current conditions are notably colder than usual. The last time the city experienced a summer this cool was in 1982. Typically, the city experiences a pattern where morning fog clears by noon, allowing for warmer afternoons. However, this year, the fog and low clouds have been more persistent, leading to consistently lower temperatures.

San Francisco's climate is heavily influenced by its proximity to the Pacific Ocean, leading to cool summers and frequent fog. The city's unique topography and oceanic conditions contribute to the formation of a persistent marine layer, resulting in the characteristic foggy and cool weather, especially during the summer months. This phenomenon is so prevalent that the city is often described as "naturally air-conditioned."

As of July 2025, San Francisco has experienced average daily temperatures of approximately 59°F, with daytime highs often stuck in the 50s and 60s. This marks the coldest summer the city has seen in over 30 years, with conditions reminiscent of those in 1982.

The persistent low-pressure system off the coast has been delivering cool air from the Pacific Ocean inland, while the absence of a high-pressure system from the East has allowed the marine layer to remain intact. This combination has resulted in prolonged periods of fog and low clouds, keeping temperatures below seasonal norms.

"We’re not seeing any strong signal of warming," said Rick Canepa, a meteorologist with the National Weather Service’s Bay Area office.

Nick Brooks, manager of the $10 Hoodie Store at Fisherman’s Wharf, noted, "That water gets cold, and when the wind comes up, it comes right down this block like a river. It’s freezing, especially when it gets later in the day."

The cooler temperatures have had several social and economic impacts:

• Tourism: Visitors unprepared for the chilly weather have been purchasing warm clothing upon arrival. Retailers specializing in warm clothing have seen increased sales due to the unexpected demand from both tourists and residents.

• Agriculture: The cooler weather has led to a slight reduction in wildfire risk, providing some relief to local farmers and vineyard owners. However, prolonged cool temperatures could potentially affect crop yields and growth cycles.

While San Francisco's cool, foggy summers are a hallmark of the city's climate, the current unseasonably cold conditions have had notable social and economic impacts. As the city continues to experience this prolonged chill, residents and visitors alike are adapting to the unexpected weather patterns.