Honestly, if you stepped outside in Foster City this morning, you probably noticed that bite in the air. It’s one of those classic Peninsula days where the sun is working overtime, but the mercury just isn't keeping up. We’re looking at weather today Foster City being dominated by a massive high-pressure system that’s keeping the rain far out in the Pacific, but don't let the blue sky fool you into leaving your jacket at home.
It’s chilly. Really.
The high for Wednesday, January 14, 2026, is topping out at about 62°F, which sounds decent on paper until you factor in the dampness coming off the lagoons. By the time the sun dips behind the Santa Cruz Mountains later this afternoon, that temperature is going to crater. We're talking a low of 45°F tonight.
What the Lagoon Does to Your Morning
Foster City is basically a giant sponge surrounded by water, and that plays havoc with how "weather today Foster City" actually feels compared to somewhere like San Mateo or Redwood City. Because we're sitting right on the bay, the humidity is hovering around 78% to 82% today.
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That high humidity makes the 45-degree night feel significantly sharper. It’s that "wet cold" that gets into your bones. If you're walking the Levee Trail near Shorebird Park, the wind is light—only about 3 mph from the west—but it’s carrying that bay chill directly onto the pavement.
The Fog Factor Tonight
The National Weather Service is flagging something specific for tonight that most people overlook: dense fog.
Once the temperature hits that dew point of roughly 44°F later tonight, the visibility is going to drop fast. It's that thick, "pea soup" variety that rolls off the water and makes driving down Foster City Boulevard a bit of a nightmare. If you have a late-night commute or a dog walk planned after 9 PM, expect those streetlights to look like fuzzy glowing orbs.
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Is This Normal for Mid-January?
Looking at historical data from places like WeatherSpark and World Weather Online, we are actually running a tiny bit warmer than the 30-year average. Usually, a typical January day here struggles to get past 58°F. So, 62°F is technically a "warm" winter day for us, even if it doesn't feel like beach weather.
- The UV index is sitting at a 2, which is low.
- You still need sunscreen if you're out for hours, but you won't fry.
- Rain chances are basically 0%.
We’ve had some pretty wild Januaries in the past—like back in 2017 when the town got drenched with nearly 12 inches of rain in a month. Today is the polar opposite of that. It’s dry, stable, and remarkably quiet.
Looking Ahead to the Weekend
If you're planning a trip to Leo J. Ryan Park or thinking about taking the boat out, Thursday and Friday are actually looking even better. We're expecting a slight bump in temperatures to about 65°F.
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However, the "weather today Foster City" trend of clear skies might start to wobble by Saturday. We’re seeing some "mostly cloudy" shifts in the long-range models for the weekend, though the chance of actual rain stays below 10%.
Basically, keep the layers handy. The Peninsula is famous for its microclimates, and Foster City is the king of them. You can be sweating in the sun at Bridgeside Shopping Center and shivering three minutes later when the breeze kicks up near the water.
Next Steps for Your Day:
If you’re heading out, wear a windbreaker over a sweater. The sun is bright enough to make a heavy coat feel like overkill, but the 3 mph breeze off the lagoon will punish you if you're just in a t-shirt. Also, if you’re driving late tonight, give yourself an extra ten minutes for the fog—visibility is likely to drop below a quarter-mile in the residential pockets near the water.