Bay Area residents are in for a stretch of moderate, pleasant weather this weekend and into next week, according to the latest forecasts from the National Weather Service (NWS) in San Francisco. With autumn settling in, the region’s famously fickle climate is once again on display—offering clear skies, mild afternoons, and a few meteorological curveballs that have become a signature of life in the Bay Area.
On October 4, 2025, the NWS issued a forecast calling for a slight uptick in temperatures and drier conditions across the Bay Area. Inland areas are expected to see highs in the mid to upper 70s, while coastal neighborhoods will linger in the mid to upper 60s. “Temperatures will be near seasonal normal with mid to upper 70s inland and mid to upper 60s along the coast,” the NWS San Francisco explained in their latest update, as reported by Hoodline.
For those planning outdoor activities, the outlook is promising. Daytime highs will range from the mid 60s to mid 70s along the coast, low to mid 70s around the bay, and high 70s to low 80s further inland, according to Bay City News. Overnight lows will mostly settle in the mid to upper 50s, offering comfortable evenings for stargazers and night owls alike. Skies are projected to stay mostly sunny, with mild afternoons prevailing through the weekend.
While the marine stratus layer will make a brief return in the early morning, it’s expected to give way to clearer conditions as the day progresses. But, as any San Franciscan knows, weather in the city is anything but predictable. The city’s renowned microclimates—those pockets of warmth and chill that can change block by block—are notorious for keeping both residents and meteorologists on their toes.
Anthony Edwards, a meteorologist with the San Francisco Chronicle, recently detailed why forecasting in the city is such a daunting task. “Even San Francisco meteorologists like me can still be taken by surprise,” Edwards admitted. The city’s steep hills, proximity to the Pacific, and urban development all conspire to create rapid, sometimes dramatic, weather shifts. During the October 2024 heat wave, for example, automated forecasts underpredicted temperatures by more than 10 degrees, leaving many residents unprepared for the sweltering conditions. Yet, Chronicle meteorologists managed to anticipate the heat by comparing recent trends with historical weather patterns.
Fog and the marine layer are perennial players in the city’s weather drama. “We have the coldest cold (ocean) current in the whole United States coming down from Alaska,” said Alex Tardy, a veteran National Weather Service meteorologist, as quoted by the San Francisco Chronicle. This 55-degree water acts as natural air conditioning, cooling the air above and forming the fog that often shrouds the city’s western neighborhoods. It’s not uncommon for San Francisco’s beaches to be socked in with fog while downtown basks in the sun—sometimes just a mile away.
San Francisco sits in a “battle zone” between arid inland air and humid ocean air, Tardy explained. There’s no sharp boundary; rather, there’s a “constant replenishment of cooler air that is constantly eroding those (hot) temperatures.” This tug-of-war is one reason why weather models often fall short in San Francisco. The National Weather Service’s “National Blended Model” divides the city into squares about 1.6 miles wide—a resolution that simply can’t capture the city’s microclimates or the sharp contrasts created by its hills and valleys.
“Most models aren’t high resolution enough to handle it well,” said Rob Mayeda, a meteorologist at NBC Bay Area. “And those that are … still underestimate the heat especially during record or historic episodes.” Without finer detail, forecasts can miss the mark by several degrees—sometimes more—particularly during heat waves or when the fog behaves unpredictably.
It’s not just temperature that’s tricky. The city’s topography also affects rainfall. The wettest area, just west of Twin Peaks, averages seven more inches of rain per year than the driest part, Hunters Point. This “rain shadow” effect is another quirk that makes forecasting a challenge. And when it comes to heat, the urban heat island effect—caused by all those skyscrapers and paved streets—can add several degrees to local temperatures, especially at night. Meteorologists often have to manually adjust their predictions to account for this, especially in densely built neighborhoods like the Mission District.
Climate change is another complicating factor. As greenhouse gases warm the atmosphere, extreme heat events are becoming more frequent in San Francisco, forcing forecasters to predict temperatures that would have been unlikely just a few decades ago. In September 2017, for example, the city shattered its all-time heat record, hitting 106 degrees—a milestone that surprised even seasoned meteorologists like Mayeda. “I think our forecasting has become more accurate, but as extremes swing higher in a warming climate … that is making it more challenging in some ways,” Mayeda said.
Back to the immediate forecast: starting Sunday, October 5, 2025, offshore winds are expected to develop, bringing in warmer and drier air from the north and northeast. This is due to high pressure building over the region and a weak thermal trough forming in the Central Valley, as detailed by Bay City News. These offshore winds can sometimes raise fire weather concerns, especially in October, but forecasters are cautiously optimistic this time around. “While the minimum humidity will drop below 30% across the North Bay interior mountains, the mild temperatures, moderate wind speed, and higher than normal fuel moisture will limit fire weather concerns,” the NWS San Francisco noted.
Recent rainfall has also helped to mitigate the risk of wildfires, which is always a relief for a region that remains vigilant against such threats. The NWS expects a slight warming and drying trend to continue through the middle of the week, with the next chance of rain arriving toward the end of the week—though the amount of precipitation is expected to be less than originally predicted.
Marine conditions are also getting an upgrade. The moderate north-northwest winds that have made for rough seas along the coast are expected to subside, leading to lighter winds and calmer waters for the work week. This should be welcome news for boaters and anyone planning to spend time on or near the water.
In the end, while the Bay Area’s weather remains as unpredictable as ever, the coming days are shaping up to be a showcase of the region’s autumn charm—mild, mostly sunny, and just a little bit mysterious. For locals, it’s a reminder that in San Francisco, it pays to dress in layers and always keep one eye on the sky.
