San Francisco's brief flirtation with warmer weather is expected to take a cool turn as we head into the weekend, with a gradual cooldown beginning Thursday. According to the National Weather Service, temperatures have hovered 5-10 degrees above the seasonal average for the interior sections, but a more temperate climate is imminent.
Today will mark the peak of this heat with highs in the 90s for inland areas and 80s near the Bay before it dials back a couple of degrees, a stark difference from Tuesday's highs. At the same time, coastal zones remain in the cooler 60s, "Ridging, the item responsible for this warmth, is expected to begin decaying today, so while temperatures will be warm, they are not expected to be as warm as those seen on Tuesday," the National Weather Service announced in a statement. Despite a compressed marine layer, which might leave some coastal regions starting grey, sunshine should break through by late morning, though the bayside areas, usually enjoying the marine layer's cool embrace, might feel a touch warmer this afternoon.
Looking ahead, the cooldown starts Thursday as a trough approaches the coast and persists through the weekend—expect highs in the upper 80s for inland and 70s around the Bay. Temperatures will be close to, if not a few degrees below average, the forecast discussions suggest. The National Weather Service hints at a return to warmth early next week as a new ridge develops, with long-term outlooks marking temperatures as "above normal" for the region.
Aviation conditions are varied, with LIFR cloud cover and spots of fog affecting Monterey Bay, and the immediate coast is projected to disperse by late morning. Winds are generally expected to be light through the morning, with moderate to breezy winds appearing in the afternoon. Nonetheless, expect these winds to taper off as the night draws close; low clouds and foggy conditions might creep inland again, affecting visibility into early Thursday for those venturing into the skies. The marine outlook maintains breezy conditions, especially for northern outer waters, while steadier winds reign over the rest of the coastal areas. "Northwesterly winds will redevelop over the coastal waters in the late week and into the weekend, offering breezy afternoons", mentions the National Weather Service for mariners braving the bay.
