Marine Weather and Tide Forecast for Mill Valley, CA

SHORT TERM
Issued at 1217 PM PDT Sat May 9 2026 (This evening through Sunday)

Low clouds have treated to the coast as of early this afternoon.
Thus, as high pressure aloft continues to build, inland temperatures will be a few degrees warmer compared to yesterday.
Thus, afternoon temperatures are forecast to reach into the mid 80s to lower 90s (far inland areas) as high pressure continues to build over the region. The coast will remain cooler, generally in the upper 50s to 60s, thanks to onshore flow and the compressed marine layer.

Tonight, expecting low clouds to return to the coast and adjacent inland valleys (similar to this morning). Again, there is the potential for mist or light drizzle again tonight into Sunday morning, yet widespread measurable rainfall is highly unlikely.

Sunday will feature similar temperatures as Saturday as the mid/upper level ridge shifts into southern California, Nevada, and Arizona. Low clouds that do develop inland will quickly retreat to the coast Sunday by midmorning giving way to mostly sunny skies inland.

LONG TERM
Issued at 1217 PM PDT Sat May 9 2026 (Sunday night through next Friday)

Low clouds persist near the coast and will return inland Sunday night, however less widespread across the interior valleys. Monday is still on track to be the warmest of the week as interior areas reach Moderate HeatRisk as the high pressure strengthens over the Desert Southwest. Temperatures by Monday afternoon are forecast to be in the low to upper 90s across the interior, mid 80s to low 90s across inland away from the coast, and low 70s to mid 80s near coastal locations. The cooler conditions near the coast will be due to the marine layer not completely going away and continued onshore winds.

Temperatures are forecast to cool slightly by Tuesday, however will still remain some 5-15 degrees above seasonal averages. There is increasing confidence that a cut-off low pressure system will approach from the eastern Pacific by midweek, bring cooler and unsettled weather to the region for the remainder of the upcoming week. This will work to push the mid/upper level ridge across the Desert Southwest farther to the east. Not expecting much widespread measurable rainfall, however this pattern would be more favorable for drizzle and/or light rain. There are still differences in model guidance about the strength and southern extent of the mid/upper level trough by midweek. Late in the week, more zonal flow is forecast to develop over the region. Be sure to check back for the latest forecasts as we gain more reliable short range guidance.

AVIATION
(18Z TAFS)
Issued at 1059 AM PDT Sat May 9 2026

Stratus is receding from all terminals with the exception of HAF.
Breezy onshore winds and VFR conditions are expected for much of the afternoon. Stratus is set to return again tonight with MVFR to IFR CIGs returning late this evening along the coast and overnight across the interior. Not anticipating fog to develop but temporary decreases in visibility are possible across the interior and along the coast.

Vicinity of SFO...VFR with gusty onshore winds through this evening.
Recent SFO obs show NW winds strengthening to around 15-20 knots with gusts up to 30 knots expected late this morning into the afternoon. Winds ease this evening with MVFR-IFR CIGs to return overnight.

SFO Bridge Approach....Similar to SFO.

Monterey Bay Terminals...Stratus is in the process of clearing at MRY and SNS with clearing to occur within the next hour. VFR conditions prevail through the afternoon/early evening before IFR- LIFR conditions return late evening through tomorrow morning.
Moderate confidence that CIGs will initially start out IFR and lower to LIFR early tomorrow morning. There is some potential for visibilities to decrease after 12Z particularly at SNS.

MARINE
(Today through Thursday)
Issued at 850 AM PDT Sat May 9 2026

Fresh to strong northwest breezes with occasional near gale force gusts will continue through the remainder of the weekend along with moderate seas. Winds become more northerly on Sunday before gradually easing late Sunday into Monday. Gentle to moderate north to northwest breezes are expected on Tuesday and Wednesday with breezy conditions returning to the inner waters late week.

MTR WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...Small Craft Advisory until 9 PM PDT this evening for Mry Bay.

Small Craft Advisory from 3 PM to 9 PM PDT Sunday for Mry Bay.

Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt Reyes 0-10 nm.

Small Craft Advisory until 9 PM PDT Sunday for Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

Small Craft Advisory until 9 AM PDT Monday for Pt Arena to Pt Reyes 10-60 NM.