Napa County, CA

Alerts

Advisory Area
County Line

Alerts are listed in order of start time and level of severity. Click on the alert title to read details for each alert.

In effect from Tuesday 07/21 10:17 AM PDT – Tuesday 07/21 9:00 PM PDT

Issued by NWS San Francisco CA

What

Temperatures into the mid 90 and low 100s.

Where

Entire Bay Area excluding the immediate Pacific Coast zones and San Francisco. Also, including Interior Central Coast.

When

Until 9 PM PDT this evening.

Impacts

This level of heat affects most individuals sensitive to heat, especially those without effective cooling and/or adequate hydration. Impacts possible in some health systems and in heat-sensitive industries.

What to Do

Hydration is a critical piece to surviving the heat. Drink water, and if possible, take water to those who are vulnerable.
Beat the heat and check the backseat! Do not leave young children or pets in unattended vehicles.Car interiors will reach lethal temperatures in a matter of minutes.
To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! Call 9 1 1.


Areas Impacted

  • Marin Coastal Range
  • North Bay Interior Mountains
  • North Bay Interior Valleys
  • San Francisco Bay Shoreline
  • East Bay Interior Valleys
  • Santa Cruz Mountains
  • Santa Clara Valley Including San Jose
  • Eastern Santa Clara Hills
  • East Bay Hills
  • Southern Salinas Valley/Arroyo Seco and Lake San Antonio
  • Santa Lucia Mountains and Los Padres National Forest
  • Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park

Tips to Stay Safe

A Heat Advisory means dangerous heat conditions are happening now or soon. Take action before, during and after the heat to stay safe. 

  • Stay in air-conditioned spaces if possible. Find cooling centers or places with AC in your community that you can go to, like libraries or shopping malls. 
  • Stay hydrated and stock up on clean drinking water to get you through multiple days of heat.
  • Reschedule outdoor activities for cooler times of the day, and take breaks in the shade or air conditioning.
  • Cover windows with curtains or shades, or use window reflectors designed to reflect heat back outside. 
  • Check on friends, family, and neighbors, especially those who do not have air conditioning or spend much of their time alone. 

Make sure you know the signs of heat-related illness and how to respond.

Briefings

No recent briefing available

From the Forecaster

Beach Safety - Distant Tropical Cyclones

Created by the NWS San Francisco WFO

Tropical Storms and Hurricanes that are far away can still create deadly rip currents and waves, especially sneaker waves. Never assume that the ocean is safe, even if the weather is nice. For maximum safety, swim near a lifeguard (where applicable) and check beach conditions.

Tropical Storms and Hurricanes that are far away can still create deadly rip currents and waves, especially sneaker waves. Never assume that the ocean is safe, even if the weather is nice. For maximum safety, swim near a lifeguard (where applicable) and check beach conditions.

Seven-day Weather Risk Overview

The graphic shows the daily risk summary for 7 days. Daily risk is based on highest risk factor for that day.

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Weather Forecasting Office

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