Marine Weather and Tide Forecast for San Mateo, CA

SHORT TERM
Issued at 1257 PM PDT Sat Mar 21 2026 (This evening through Sunday)

Satellite imagery shows high clouds across the Bay Area and Central Coast as a weak cold front stalls over the North Bay into northern California and promotes a slight onshore flow, while the ridge that gave us the last few days of record-breaking heat flattens and moves off the the east. High temperatures today range from the upper 70s to the middle 80s in the interior valleys, the 70s close to the Bays, and the lower to middle 60s along the Pacific coast. These temperatures are still warmer than the seasonal averages for this time of year, but are still a welcome change of pace from the last week. The high clouds will clear through the evening and overnight hours, and a redeveloping marine layer will allow for some patchy stratus in the coastal regions early Sunday morning. Morning lows will take a dip as the lower elevations reach the upper 40s to the lower 50s, with lows in the middle 50s to lower 60s in the higher elevations.

The cooling trend continues through Sunday with more zonal flow developing in the upper levels, with temperatures maybe a few degrees cooler across the region, but conditions remaining similar otherwise.

LONG TERM
Issued at 1257 PM PDT Sat Mar 21 2026 (Sunday night through next Friday)

Conditions remain broadly similar through the next week as zonal flow to slight ridging persist across the forecast region. The inland valleys of Monterey and San Benito Counties remain rather warm with highs in the upper 80s to lower 90s possible Monday through Wednesday. Otherwise, copying and pasting the temperature outlook for Sunday through the remainder of the 7 day forecast will give you a pretty good idea of what to expect.

The next chances for rainfall remain beyond the 7 day outlook, and as the previous forecaster noted, extended range model output suggests a chance for a developing trough pushing a weak low pressure system into the state as March turns into April. A closer look at the ensemble model clusters shows an approximate 50/50 split between the model runs that do show a trough heading into the West Coast and those that keep the slight ridging around.

AVIATION
(06Z TAFS)
Issued at 923 PM PDT Sat Mar 21 2026

Currently VFR at all terminals with the exception of HAF which is reporting MVFR visibility. Moderate confidence on the return of LIFR ceilings to HAF, MRY, and SNS. Onshore winds will prevail.
Haze will reduce slant range visibilities.

Vicinity of SFO...Currently VFR with gusty westerly flow. High confidence in VFR through the TAF period. Westerly winds will prevail, diminishing tonight before increasing again (although not as strong) with the afternoon sea breeze tomorrow.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently VFR with southwesterly flow at MRY and VFR with northerly flow at SNS. Moderate confidence on LIFR ceilings returning to the terminals tonight. Onshore winds will prevail.

MARINE
(Tonight through next Friday)
Issued at 923 PM PDT Sat Mar 21 2026

Strong northerly winds will continue through the weekend with gale force gusts beginning to diminish tomorrow morning. Hazardous seas are expected over the weekend as a result. Winds diminish and seas abate going into next week.

MTR WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...Gale Warning until 3 AM PDT Sunday for Pigeon Pt to Pt Pinos 10- 60 NM-Pt Arena to Pt Reyes 0-10 nm.

Small Craft Advisory until 3 AM PDT Monday 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 3 PM PDT Sunday for Pt Arena to Pt Reyes 10- 60 NM.