Marine Weather and Tide Forecast for Muir Beach, CA

UPDATE
Issued at 900 PM PDT Tue Jul 8 2025

Overcast conditions are moving in faster than originally expected with satellite showing stratus moving in along the coast and SF Bay region. High temperatures were largely in the upper 70s to mid 80s across the interior. Most sites were running at least a few degrees below normal today. For example, San Jose only reached 77 degrees today and Redwood City only reached 76 degrees with today's normal high for both cities being 81 degrees. If you're not a fan of the cooler than normal weather so far this month, you're in luck as a warming trend remains on track to begin tomorrow. Temperatures will rise into the 80s to low 90s across the interior on Wednesday and 90s to low 100s in the warmest locations Thursday and Friday.

SHORT TERM
Issued at 1200 PM PDT Tue Jul 8 2025 (This evening through Wednesday)

The marine layer is currently between 2,200 and 2,700 feet as weak low pressure remains offshore. This system will gradually move inland over the next 36 hours while weakening. Meanwhile, its previous position offshore will be replaced by ridging from subtropical high pressure in the Eastern Pacific. This pattern change will cause the marine layer to compress while onshore NW winds increase. All this means that temperatures will begin to increase starting Wednesday. Highs are forecast to be around 5-10 degrees warmer than today for inland areas. While becoming more shallow, the marine layer will continue to keep coastal areas in the 60s.

LONG TERM
Issued at 1200 PM PDT Tue Jul 8 2025 (Wednesday night through next Monday)

The warming trend will continue into Thursday as the synoptic high pressure becomes more established offshore. For inland areas, this will cause another 5-10 degree jump in temperatures from Wednesday. Some interior and high elevation areas will experience moderate HeatRisk from Thursday - Friday with afternoon temperatures in the 90s. A very weak mid-level disturbance will bring some relief over the weekend, but broadly speaking the pattern looks fairly stable through at least early next week.
There will be a very broad area of high pressure across the Northeast Pacific, with an embedded mesoscale high sitting over the Channel Islands. While ensembles are confident that the persistent high pressure will increase the 850 mb temperature to around 24C (90th percentile) by Saturday, this pattern supports steady onshore wind. With ocean temperatures cooler than normal (54F), the marine layer should continue to keep coastal areas seasonably cool, even while the Central Valley flirts with triple digit heat throughout the long term forecast. There is some elevated fire weather concerns above and inland of the marine layer's influence. The RH will drop below 30% at times, and afternoon wind gusts will reach up to 30 mph. Fortunately with onshore winds, these conditions will be diurnally driven with lighter winds and good humidity recovery in the foothills expected each night.

AVIATION
(06Z TAFS)
Issued at 1002 PM PDT Tue Jul 8 2025

IFR and MVFR CIGS are building along the coast and have filled at HAF as well as the SF Bay And Monterey Bay terminals. Winds will stay light to moderate through the night as widespread IFR CIGs affect the region with MRY and HAF falling to LIFR into the early morning. Inland clearing begins in the mid morning with most TAF sites going VFR in the late morning and early afternoon. The exception will be HAF, which keeps CIGs through the TAF period.
Winds look to stay light to moderate through the morning and increase into late Wednesday morning and afternoon. Expect winds to reduce into Wednesday evening with CIGs slower to move inland that night.

Vicinity of SFO...IFR lasts into the late morning. Winds are reducing and look to stay light through the night and much of the morning. Expect CIGs to erode into the late morning as moderate to breezy west winds arrive. These winds reduce into late Wednesday evening.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...IFR CIGs have filled over the terminals and winds are reducing, becoming light. MRY sees winds become very light into the night and CIGs fall to LIFR with some pockets of mist and drizzle in the area into early Wednesday. Winds become moderate into mid to late Wednesday morning as CIGs erode over the terminals.

MARINE
(Tonight through next Monday)
Issued at 900 PM PDT Tue Jul 8 2025

Expect light to moderate winds with weak seas into Wednesday.
Winds will strengthen and turn more northerly by Wednesday afternoon and continue strengthening, becoming fresh to strong on Thursday and into the weekend. Significant wave heights will be rough to very rough Thursday through Saturday for the outer waters.

MTR WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...Small Craft Advisory from 3 PM Wednesday to 3 AM PDT Thursday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0- 10 nm-Pt Arena to Pt Reyes 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.