Marine Weather and Tide Forecast for Sunol, CA

SHORT TERM
Issued at 149 PM PDT Tue Mar 17 2026 (This evening through Wednesday)

We are well on our way to break more record high temperatures this afternoon with some all time monthly (March) records at risk of being broken (please see the CLIMATE below). This is as the center of the mid/upper level high pressure positions itself over the Central Coast today. Temperatures are forecast to reach into the upper 70s to mid 80s near northwest facing coastal locations and upper 80s to lower 90s across the interior and Santa Cruz area.

Overnight temperatures are forecast to cool into the low to mid 50s across the valleys, upper 50s to low 60s elsewhere, and mid 60s to low 70s in the higher elevations. Where radiational cooling is most effective, a few upper 40s cannot be ruled out. Downtown San Francisco may remain the lower 60s into Wednesday morning.

The center of the mid/upper level high will shift over the Desert Southwest by Wednesday and strengthens to 595 decameters (dam) with 850 mb temperatures approaching or exceeding 20 degrees C by Wednesday. Thus, temperatures may be a few degrees warmer than today in areas.

LONG TERM
Issued at 113 AM PDT Tue Mar 17 2026 (Wednesday through Monday)

Wednesday through Friday feature similar conditions to today, with temperatures far above the seasonal averages, widespread Moderate HeatRisk, sunny skies, and light winds as the associated upper level ridge crawls across California. A slight warming trend will continue with portions of the Central Coast, including the Ben Lomond-Boulder Creek area, the Morgan Hill-Hollister corridor, and the southern Salinas Valley, seeing temperatures rising into the upper 90s. A couple of favored patches will even see Major HeatRisk, corresponding to a high level of danger for heat-related illnesses for the general population. Notable regions for Major HeatRisk impacts include the ridgelines of the Santa Cruz Mountains, Carmel Valley, and the foothills of the Gabilan Range east of Salinas. The Heat Advisory in effect for the entire forecast region remains in place through Friday evening at the earliest.

For the upcoming weekend, the ridge begins to break down as it crawls eastwards across the Desert Southwest. This will give us a gradual cooling trend, but will also promote an strengthening pressure gradient, leading to stronger winds and an elevated risk for grass fires across the region. The extreme heat of the last few days will dry out a lot of fine fuels across the region, and pulses of offshore flow are possible Friday into the weekend, especially in the South Bay and Central Coast. There are a couple of mitigating factors. The first is that live fuels remain rather moist as the peak growing season continues. The second is that the larger scale pattern is for winds to remain onshore, especially in the North Bay.
As for the temperatures, they will gradually cool around 5-10 degrees per day starting on Saturday, and by the early part of next week, temperatures might only be slightly higher than the seasonal averages.

AVIATION
(18Z TAFS)
Issued at 1059 AM PDT Tue Mar 17 2026

A few high clouds are passing over the region, with VFR conditions prevailing. Expect quiet weather and generally light winds to continue through the forecast period.

Vicinity of SFO...Winds will become onshore by this afternoon and should get up to 10kt before becoming light and variable or weakly offshore later this evening. VFR conditions will prevail.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Quiet weather continues with winds being a bit variable around the Monterey Bay. For KSNS and around KMRY, winds remain offshore this morning but will become onshore by the afternoon. The forecast will be on repeat for tonight, with offshore flow returning and onshore flow again by tomorrow afternoon.

MARINE
(Today through Sunday)
Issued at 859 AM PDT Tue Mar 17 2026

Moderate NNW to N breezes will prevail offshore, with gentle breezes within 10NM. Seas are moderate from a combination of wind waves and a low southerly swell. Similar conditions will persist through Thursday before winds increase to a strong NNW breeze with rough seas from Friday through Sunday.

MARINE
(Today through Sunday)
Issued at 859 AM PDT Tue Mar 17 2026

Moderate NNW to N breezes will prevail offshore, with gentle breezes within 10NM. Seas are moderate from a combination of wind waves and a low southerly swell. Similar conditions will persist through Thursday before winds increase to a strong NNW breeze with rough seas from Friday through Sunday.

CLIMATE
Issued at 113 AM PDT Tue Mar 17 2026

The following are the record high temperatures at the long term sites for March 17th, 18th, 19th, and 20th.

Location Mar 17 Mar 18 Mar 19 Mar 20

Santa Rosa 87 in 1996 84 in 2010 83 in 2004 84 in 2004 San Rafael 84 in 1972 80 in 1996 81 in 1964 82 in 1960 Kentfield 87 in 1914 89 in 1914 83 in 1996 82 in 2001 Napa 92 in 1914 87 in 1914 86 in 1914 86 in 2004 Richmond 83 in 2004 78 in 1996 80 in 1996 81 in 2004 Livermore 87 in 1972 86 in 2004 82 in 2015 87 in 1915 San Francisco 85 in 1914 86 in 1914 80 in 2010 78 in 2004 SFO Airport 82 in 2004 77 in 2004 78 in 2010 78 in 2004 Redwood City 85 in 2004 84 in 2004 81 in 2010 82 in 2004 Half Moon Bay 83 in 2004 75 in 1978 79 in 2010 75 in 2010 Oakland Museum 85 in 2004 81 in 2004 81 in 1984 78 in 2001 San Jose 88 in 1914 87 in 1914 82 in 1988 78 in 2004 Salinas Airport 87 in 2004 84 in 1960 87 in 1997 80 in 1934

The following are the record high temperatures at the long term sites for the entire month of March.

Location

Santa Rosa 91 on March 16, 2004 San Rafael 88 on March 25, 1952 Kentfield 91 on March 28, 1923 Napa 92 on March 17, 1914 Richmond 87 on March 31, 2021 Livermore 90 on March 25 and 26, 2025 San Francisco 87 on March 11, 2005 SFO Airport 85 on March 25, 1952 Redwood City 90 on March 16, 2026 Half Moon Bay 83 on March 31, 2000 and March 17, 2004 Oakland Museum 88 on March 11, 2005 San Jose 89 on March 14, 2015 Salinas Airport 92 on March 14, 2015

MTR WATCHES/WARNINGS/ADVISORIES
CA...Heat Advisory until 8 PM PDT Friday for CAZ006-502>506-508>510- 512>518-528>530.

PZ...None.