textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1259 PM PDT Mon Mar 16 2026

- Early season, long duration heat wave bringing record-breaking temperatures and Moderate HeatRisk has set in and will last through at least Friday

- Elevated potential for grass fires through the week due to warm and dry conditions with periods of moderate offshore winds

SHORT TERM

Issued at 1259 PM PDT Mon Mar 16 2026 (This evening through Tuesday)

As mentioned in the morning update, the forecast remains on track this afternoon. The unusual early season, long duration heat wave has set in across our entire forecast area. Many locations will set daily record high temperatures as the week progresses, along with numerous monthly records. A shallow marine layer may provide some isolated respite from the widespread heat, but no matter how you slice it, our entire area will feel the impacts of unusually high temperatures for this time of year through a majority of the extended forecast. Listed below are things we can all do to stay safe during a heat wave. We also want to continue to get the word out that despite the summer type air temperatures, the ocean is still very much in winter mode still. Cold water shock is a real risk, and with this heat wave coinciding with most schools Spring Break week, there will be many visitors to our Pacific coastline from near and afar. We are also watching the potential for increasing southern swell that may possibly necessitate a Beach Hazard Statement for riptides and sneaker waves at some point, its not quite there yet, but be careful nonetheless and never turn your back on the ocean. Below are tips to help mitigate your risks during a heat wave:

Heat is the number 1 weather related killer in the United States. Unfortunately lives will be lost during this heat wave. Follow these tips to protect yourself, your loved ones, and your animals.

-Stay inside in an air conditioned environment between 10am and 7pm. -Suspend unnecessary outdoor activities during the extreme heat, but if you must be outdoors, take frequent breaks in the shade or AC and drink cool water. -Know the signs and symptoms of Heat Exhaustion vs. Heat Stroke! Heat Stroke can be deadly if not treated immediately by a medical professional. Call 911 if you suspect someone is suffering from Heat Stroke. -Wear a , swim near a lifeguard, and check conditions before entering the water if going to a river or ocean to cool off. Rivers and the ocean are extremely cold, and Cold Water Shock can turn into paralysis and drowning if you are not careful. -Use a cool and damp towel on your body if you do not have AC and are feeling hot. Or, take a cool shower or bath. -Do not leave kids or pets in a parked car. -Ensure pets and livestock have access to shade and water.

LONG TERM

Issued at 1259 PM PDT Mon Mar 16 2026 (Tuesday night through next Sunday)

With not much changing in the extended forecast from the previous shift, will resend the extended discussion below that does an excellent job summing up what we continue to see through the weekend into the beginning of next week:

"After several days of this heat wave building, it will reach the top of the plateau by Tuesday. Interior temperatures will reach the low to mid 90s, with 70s and 80s along the coast. Wednesday through Friday look nearly identical. Hot spots this week include the southern Salinas Valley and Gabilan Range. There is a strong possibility that Pinnacles National Park records the earliest 100 degree day of the year this week. The current record for March is only 93. Along the coast the hot spot looks to be Santa Cruz, where downslope winds will add adiabatic heating to battle any marine influence. We expect low 90s there.

Numerous monthly records are expected to be broken this week. Check out the Climate section below for those benchmarks. Overall the big story with this heat wave is how early it is. Yes we've seen much hotter days in the Summer and early Fall, but we are a full 30 degrees warmer than normal this week. That's very unusual any time of year.

Finally, when will it end? All ensemble clusters agree that the ridge will start to weaken this weekend. That doesn't mean temperatures will drop all the way back to normal, but we should see a cooling trend of about 5 degrees per day from Saturday through Monday, effectively ending the heat wave."

AVIATION

(18Z TAFS) Issued at 1032 AM PDT Mon Mar 16 2026

Widespread VFR conditions expected across the entire region through the TAF period. Only exception is potential for lower (MVFR) visibilities near the coast due to haze and/or sea spray. West- northwest winds will increase by early afternoon and linger into the evening as onshore flow returns to the region. Winds diminish overnight and become variable into early Tuesday morning.

Vicinity of SFO...VFR through the TAF period. A moderate west- northwest wind will increase a bit this afternoon before diminishing overnight and into early Tuesday morning.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR through the TAF period. A gentle to moderate west-northwest wind will increase a bit this afternoon before diminishing this evening and become variable into Tuesday morning. Winds may turn more southerly early Tuesday morning at KSNS.

MARINE

(Tonight through next Saturday) Issued at 1259 PM PDT Mon Mar 16 2026

Breezy to gusty north winds linger in the northern outer waters through the day before easing tonight and into Tuesday morning. Winds across the waters continue to diminish through the work week. Sea heights remain moderate due to a combination of wind waves and low southerly swell.

CLIMATE

Issued at 410 AM PDT Mon Mar 16 2026

The following are the record high temperatures at the long term sites for March 16th, 17th, 18th, and 19th.

Location Mar 16 Mar 17 Mar 18 Mar 19

Santa Rosa 91 in 2004 87 in 1996 84 in 2010 83 in 2004 San Rafael 87 in 1972 84 in 1972 80 in 1996 81 in 1964 Kentfield 86 in 2004 87 in 1914 89 in 1914 83 in 1996 Napa 88 in 2004 92 in 1914 87 in 1914 86 in 1914 Richmond 84 in 1972 83 in 2004 78 in 1996 80 in 1996 Livermore 88 in 1972 87 in 1972 86 in 2004 82 in 2015 San Francisco 85 in 1914 85 in 1914 86 in 1914 80 in 2010 SFO Airport 82 in 2004 82 in 2004 77 in 2004 78 in 2010 Redwood City 84 in 2004 85 in 2004 84 in 2004 81 in 2010 Half Moon Bay 78 in 1972 83 in 2004 75 in 1978 79 in 2010 Oakland Museum 85 in 2004 85 in 2004 81 in 2004 81 in 1984 San Jose 85 in 1914 88 in 1914 87 in 1914 82 in 1988 Salinas Airport 87 in 2004 87 in 2004 84 in 1960 87 in 1997

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 89 on March 31, 2011 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...Small Craft Advisory until 3 AM PDT Tuesday for Pt Arena to Pt Reyes 10-60 NM.