textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1229 PM PDT Tue Sep 29 2026

- Elevated fire weather conditions across the higher terrain through Wednesday

- Areas of moderate HeatRisk across the interior Wednesday through Tuesday

- Minor coastal flooding near high tide for bayshore locations along the San Francisco, San Pablo, and Monterey Bays today through Thursday

SHORT TERM

Issued at 1229 PM PDT Tue Sep 29 2026 (This evening through Wednesday night)

Isolated patches of stratus and fog linger along the coast, but the region remains generally clear. With the marine layer compressing in response to incoming ridging, any stratus development tonight is limited to the coastal regions, with fog development possible along the coast.

A pattern change is underway as ridging over the eastern Pacific builds into the western United States, with temperatures warming above to significantly above the seasonal averages (5 to 15 degrees warmer) as a result. High temperatures today will be in the middle 80s to the middle 90s for the inland valleys, the middle 70s to the middle 80s near the Bays, and the middle 60s to the lower 70s for the Pacific coast. Wednesday's highs will be similar. A breezy onshore flow should set up each afternoon and evening, while the overnight and morning period will feature a push of offshore flow across the interior mountains of the North and East Bay.

Beginning today and especially Wednesday, areas of Moderate HeatRisk start to pop up across the inland regions. These correspond to a moderate risk of heat-related illnesses for sensitive populations, including children, the elderly, pregnant women, people with chronic illnesses, and people who work or live outdoors without access to adequate cooling or hydration. These areas are not widespread enough to put out a Heat Advisory, but still impact several populated regions, notably the interior valleys of the East Bay and the San Jose region. Follow these tips to avoid heat exhaustion and heatstroke:

* Stay hydrated and drink plenty of fluids. * Wear lightweight, light-colored clothing. * Reduce time spent outdoors or stay in the shade. * Never leave people or pets unattended in vehicles. * Use sunscreen if going to the coast or the pool.

Minor coastal flooding is possible across the bayshore locations of San Francisco Bay, San Pablo Bay, and Monterey Bay around high tide. Up to 1.2 feet of inundation above normally dry land is expected, including up to 0.7 ft of surge caused by thermal expansion and sea level rise since the sea level datum (basically the point where we define as "sea level") was set in the 1983-2001 period. At the San Francisco tidal gauge, high tide is expected to be 1.2 ft above normal (7.01 ft MLLW) at 1:30 PM Tuesday 9/29 and 1.2 ft above normal (7.03 ft MLLW) at 2:10 PM Wednesday 9/30.

LONG TERM

Issued at 1229 PM PDT Tue Sep 29 2026 (Thursday through next Monday)

Little change in the sensible weather through the week as a rather resilient ridge sets up across the western United States, supported by the ensemble model cluster analysis and the ensemble model means from the European, American, and Canadian ensemble models. Temperatures may fluctuate a few degrees owing to fluctuations in the upper level pattern, but for the most part, high temperatures through the seven day outlook should be similar to today's highs. The current forecast even suggests a few degrees of warming for the upcoming weekend, with warm spots in the interior valleys reaching the upper 90s and even some isolated triple digits. This is also when we start to see more widespread areas of Moderate HeatRisk, although it's a little early to put out a Heat Advisory. Longer range outlooks suggest that temperatures above seasonal averages will continue into the middle of October.

Minor coastal flooding around high tide continues in low-lying areas across the San Francisco, San Pablo, and Monterey Bay shorelines through Thursday and potentially into Friday. At the San Francisco tidal gauge, high tide is expected to be 1.1 ft above normal (6.92 ft MLLW) at 2:58 PM on Thursday 10/1.

AVIATION

(00Z TAFS) Issued at 417 PM PDT Tue Sep 29 2026

VFR conditions prevail across most of the region through the night and into Wednesday. Some IFR-LIFR ceilings are possible overnight and early Wednesday morning at the immediate coast and particularly near Monterey Bay, while a low confidence for foggy conditions exists within the North Bay valleys. A moderate onshore wind continues through the evening hours, diminishing overnight before gentle to moderate onshore winds resume Wednesday afternoon.

Vicinity of SFO... VFR through the TAF period. Breezy and gusty northwest winds continue into the late evening hours, diminishing overnight before resuming Wednesday afternoon.

SFO Bridge Approach... Similar to SFO

Monterey Bay Terminals... VFR through the late evening with IFR-LIFR stratus developing after midnight, clearing after sunrise on Wednesday morning. A gentle to moderate onshore wind continues through the evening hours, with light winds overnight before gentle onshore winds resume Wednesday afternoon.

MARINE

(Tonight through next Sunday) Issued at 417 PM PDT Tue Sep 29 2026

Hazardous conditions prevail over the coastal waters due to fresh to near gale northerly breezes. Frequent gale force gusts are expected over the outer waters north of Pigeon Point through Wednesday morning. Conditions will gradually improve Wednesday night as northerly breezes ease to gentle to moderate. Rough to very rough seas through Wednesday will subside to become moderate to rough.

FIRE WEATHER

Issued at 515 AM PDT Mon Sep 28 2026

The marine layer persists this morning, around 1500-2000ft, but should gradually compress to around 500ft throughout the day. Today will be coolest day of the week, though it is also the start of a warming trend. Offshore flow gradually works its way into the region today, which will lead to breezy winds each morning from through Wednesday. The strongest winds are expected on Tuesday morning in the interior mountains of the North and East Bays, where wind gusts could reach 30-35 mph. These offshore winds should contribute to poor overnight humidity recoveries, with overnight relative humidities as low as 20-40% above the marine layer.

MTR WATCHES/WARNINGS/ADVISORIES

CA...Coastal Flood Advisory until 5 PM PDT Thursday for CAZ006-506- 508-529-530.

PZ...Gale Warning until 9 PM PDT this evening for Pt Arena to Pt Reyes 0-10 nm.

Small Craft Advisory until 3 AM PDT Wednesday for Pigeon Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

Gale Warning until 9 AM PDT Wednesday for Pt Arena to Pt Reyes 10-60 NM.

Small Craft Advisory until 3 PM PDT Wednesday for Pigeon Pt to Pt Pinos 10-60 NM.