textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 203 PM PDT Sun Mar 15 2026

- Early season, long duration heat wave brings record-breaking temperatures and Moderate HeatRisk through the week

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

SHORT TERM

Issued at 203 PM PDT Sun Mar 15 2026 (This evening through Monday)

A very shallow marine layer remains in place today and should keep conditions near the coast cooler than areas inland. However, the warm-up is well underway this afternoon as temperatures have warmed into the upper 70s across the interior with maximum temperatures forecast to be in the low to mid 80s. These temperatures are resulting in Minor HeatRisk this afternoon and are some 10-20 degrees F above seasonal averages. 500MB heights are around 591 decameters (dam), however the ridge is placed about 380 miles west of the region over the Pacific.

Overnight, temperatures will cool into the low to mid 50s in the lower elevations. However, temperatures in the higher elevations look to largely remain in the 60s. There is a low end potential for coastal and valley fog tonight, yet will be less widespread compared to this morning as the marine layer looks to be more compressed.

The warming trend ramps up on Monday and will continue throughout much of the week! This is when temperatures climb to some 15-25 degrees above average across the Bay Area and Central Coast. More widespread Moderate HeatRisk expands across the region resulting in the issuance of a Heat Advisory for all of the region from 10 AM Monday through 8 PM Friday. Forecast maximum high temperatures are in the upper 70s to mid 80s near the coast with mid 80s to low 90s across the interior.

LONG TERM

Issued at 203 PM PDT Sun Mar 15 2026 (Monday night through next Saturday)

The high pressure will become centered overhead by Wednesday with 500MB heights approaching 595 dam over the Desert Southwest. This is when some of the warmest, most interior areas reach the low to mid 90s while coastal areas remain in the 80s as 850MB temperatures reach or exceed 20 degrees C. There is even the potential (30%-70%) for Pinnacles National Park to reach 100 degrees F Wednesday through Friday (some of the warmest days of the upcoming week).

From previous forecaster, "This is our first major heatwave of the year and it is going to be a marathon. We are primarily expecting Moderate HeatRisk with some relief overnight from overnight lows in the upper 50s to low 60s. There are patches of Major HeatRisk (impacts most people) in the higher elevations of the Santa Cruz Mountains and interior Central Coast next week. Given the long duration of this heat event, susceptibility to heat related illnesses will increase throughout the week. If you are going to be outside for prolonged periods of time make sure you are drinking plenty of water and allowing time to rest in the shade. Never leave people or pets unattended in the car. If possible, avoid going outside during the peak afternoon heat (approx. 10AM - 4/5PM). Heat Advisories will be in effect for much of the Bay Area and Central Coast Monday through Friday with some potential to expand into next weekend.

Expect increased potential for grass fires next week as much above normal temperatures cure small, fine fuels (grass). Offshore winds will remain light to moderate which will help mitigate how much any fires that do develop can grow. If you are participating in any outdoor activities (camping, off-roading, hiking, etc) exercise caution when using fire and be aware that the risk of grass fires will be elevated next week."

AVIATION

(00Z TAFS) Issued at 427 PM PDT Sun Mar 15 2026

Widespread VFR and moderate winds last into the night. Expect winds to become light across the region overnight, with some slight reductions in visibility from mist and spotty fog. Visibilities improve in the mid to late morning. Winds increase slightly into Monday afternoon.

Vicinity of SFO...VFR through the TAF period. Moderate west winds linger into the night before reducing. Winds become light and variable into Monday morning with some slight reductions in visibilities. West winds build again Monday afternoon and last into late that night before becoming light again.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR lasts into the late night. Expect light to moderate winds through the evening that become light into the night. Some pockets of mist look to reduce visibilities in the late night and through the morning. Conditions improve by the late morning and early afternoon as northwest winds build.

MARINE

(Tonight through next Friday) Issued at 427 PM PDT Sun Mar 15 2026

Winds are easing across most of the waters while breezy northerly winds linger for the Northern outer waters into Monday. Winds reduce into the work week. Sea heights will stay moderate due to a combination of wind waves and low southerly swell.

CLIMATE

Issued at 133 AM PDT Sun Mar 15 2026

The following are the record high temperatures at the long term sites for March 15th, 16th, 17th, and 18th.

Location Mar 15 Mar 16 Mar 17 Mar 18

Santa Rosa 88 in 2004 91 in 2004 87 in 1996 84 in 2010 San Rafael 83 in 1972 87 in 1972 84 in 1972 80 in 1996 Kentfield 85 in 2004 86 in 2004 87 in 1914 89 in 1914 Napa 86 in 2004 88 in 2004 92 in 1914 87 in 1914 Richmond 85 in 2004 84 in 1972 83 in 2004 78 in 1996 Livermore 83 in 1972 88 in 1972 87 in 1972 86 in 2004 San Francisco 82 in 2004 85 in 1914 85 in 1914 86 in 1914 SFO Airport 81 in 2004 82 in 2004 82 in 2004 77 in 2004 Redwood City 84 in 2004 84 in 2004 85 in 2004 84 in 2004 Half Moon Bay 74 in 1974 78 in 1972 83 in 2004 75 in 1978 Oakland Museum 85 in 2004 85 in 2004 85 in 2004 81 in 2004 San Jose 82 in 2004 85 in 1914 88 in 1914 87 in 1914 Salinas Airport 83 in 1972 87 in 2004 87 in 2004 84 in 1960

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 from 10 AM Monday to 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.