You've probably noticed that San Leandro doesn’t exactly play by the same rules as San Francisco or the deep inland heat of Pleasanton. It’s caught in this weird, wonderful middle ground. One minute you’re looking at a crisp morning fog rolling off the San Francisco Bay, and forty minutes later, the sun is blazing down on the Marina.
The san leandro weather forecast for this week, starting Thursday, January 15, 2026, is actually a perfect example of this tug-of-war. We’re looking at a surprisingly warm peak today with a high of 64°F and nothing but sun. But don't get too comfortable in those light layers; by the time we hit the middle of next week, the mercury is going to take a noticeable dive back into the mid-50s.
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The Immediate 10-Day Outlook
If you're planning anything outdoors at Lake Chabot or just trying to time your grocery run at the Bayfair Center, here is the raw deal for the next week and a half.
Today starts off strong. We’re hitting about 64°F with very low wind, mostly from the East at about 8 mph. It’s the kind of day where you can actually leave the heavy coat in the car. Friday looks even better—expect a high of 67°F.
But then, things get a bit shifty.
Saturday and Sunday (Jan 17–18) will bring in some clouds. Temperatures stay mild, hovering around 65°F to 66°F during the day, but the nights are still dropping into the mid-40s. You’ll want the heater on by 7 PM.
The real shift happens next Wednesday, January 21. That’s when the "January chill" actually starts to bite. We’re looking at highs struggling to reach 58°F. By Friday, January 23, the daytime high might only hit 54°F.
It’s dry for now, though. While the Pacific Southwest long-range forecast suggests mid-January could see some heavy rainy periods, the immediate 14-day window for San Leandro looks remarkably clear of significant downpours, save for some potential sprinkles around January 26 or 27.
San Leandro’s Weird Microclimate Explained
Why is it so different here? Basically, geography.
San Leandro sits in a "sweet spot." It’s shielded by the Berkeley Hills to the east and tempered by the Bay to the west. While San Francisco is getting hammered by the "Marine Layer" (that thick, wet fog we all call Karl), San Leandro often sits just far enough inland to stay in the sun.
However, we have our own quirks.
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The city is essentially a funnel. Air moves from the south up through the Castro Valley and the Upper San Leandro Reservoir. This creates "wind gaps" that can make one neighborhood feel like a refrigerator while another, just two miles away, feels like a patio in Palm Springs.
Seasonal Survival: What to Expect Year-Round
Honestly, if you’re new to the area, the summer "heat" is a bit of a myth.
The hottest month isn't July; it’s usually September. That’s when the average high hits about 74°F or 75°F. It’s a dry, comfortable heat. Compare that to the 90°F+ temperatures you’ll find if you drive just 20 minutes east through the Dublin Grade, and you’ll realize why people pay a premium to live here.
Winter is short but damp.
December is typically our wettest month, averaging about 3.5 to 4 inches of rain. We don't get snow—ever—but we do get "King Tides." When heavy rain hits during a high tide, the shoreline near the Marina can get a little dicey.
Air Quality and the "Smoke Season"
We have to talk about the elephant in the room: air quality.
Because of our position in the East Bay, San Leandro often acts as a catchment basin for particulate matter. Today, January 15, 2026, the AQI is sitting at a "Good" level (around 23), but during the late summer and fall, that can change fast.
Wildfire smoke from the North Bay or the Sierra foothills tends to settle in the corridor between Oakland and Hayward. In recent years, we've seen the "fire season" stretch from five months to nearly seven. If the san leandro weather forecast mentions a "North Wind" or "Diablo Winds" during autumn, that’s your cue to seal the windows and check your air purifier filters.
Real Risks: Flooding and Earthquakes
While we’re obsessing over whether to wear a sweater, there are bigger environmental factors at play.
Downtown San Leandro actually has a "Minor" flood risk, which sounds comforting until you realize that about 19% of properties in the area are currently at risk during extreme rain events. The city is protected by over 150 flood risk reduction projects, but as sea levels rise, the interaction between groundwater and storm surges becomes a real math problem for the city council.
And then there's the Hayward Fault. It runs right through the heart of the East Bay. While not "weather" in the traditional sense, the atmospheric pressure changes and soil saturation from a wet winter can actually play into how the ground behaves during a tremor.
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Actionable Tips for This Week
Don't just look at the numbers; plan around them.
- Layer Up Today: With a 20-degree swing between the 64°F high and 44°F low, you will regret not having a jacket by sunset.
- Check Your Guttering: Even though next week looks mostly dry, the sprinkle forecast for the 26th is a good reminder to clear out the leaves before the February rains (which are predicted to be above average) hit.
- Morning Commute: Expect some patchy fog near the 880 corridor early Friday morning. It’ll burn off by 10 AM, but it’ll make the sun-glare on the commute home even worse.
The san leandro weather forecast for the rest of January 2026 shows a cooling trend that’s going to make those 67°F days feel like a distant memory by next weekend. Enjoy the sun while it’s here, keep an eye on the wind gaps, and maybe finally buy that "breathable" windbreaker you've been eyeing.