SOS Alerts, wildfire estimated impacted areas

What does this map represent?

The red boundary shown on the map represents an approximate area impacted by wildfire. This boundary is not an evacuation zone, nor is it a boundary of burned/unburned areas. The map may also include several red polygons which indicate areas potentially impacted by active fires. If you are in the affected area, please check real-time updates from your local fire and law enforcement agency.

What is the map source?

The map, including the approximate area impacted by the fire, is derived from satellite data from the National Oceanic and Atmospheric Administration’s (NOAA) GOES constellation of satellites. These satellites include infrared and optical sensors optimized for detecting “hot spots” or large wildfires on the Earth’s surface, which we use to create the wildfire’s approximate impact boundary.

How often does the map get updated?

With processing and publishing time associated with the GOES satellite imagery, we’re able to refresh the wildfire map up to every hour, although there may be circumstances where there’s a slight delay. To verify the freshness of the data, you can find a timestamp included with the map that provides you the time of the last update.  If there has not been a significant change in movement on the outside perimeter of the fire, the map may look unchanged for some time - the date and time provided with the map will show when it was last generated. Please note, this map does not replace on-the-ground announcements from your local fire agency.

How accurate are the boundaries?

Currently, via the GOES satellite, our maps -- and associated impacted area assessments -- are limited to an on-the-ground resolution of around 4-6 kilometers (~2.5-3.7 miles) or slightly higher, depending on where the fire occurs.  In areas where the fire is primarily burning small fuel, like grass, it may be difficult for the satellite to pick up heat, resulting in lines not being drawn around that area. In the future, by combining additional satellite data, we hope to offer even higher resolution maps of the affected area.

Why don't I see a boundary for a particular fire?

Currently, we’re limited to providing wildfire boundary coverage for large fires where we have NOAA GOES satellite coverage, and have sufficient confidence in that data’s accuracy. As additional wildfire-relevant satellite data comes online in the future, we’re hoping to bring these maps to more areas.

How can I leave feedback about the boundary?

Tap the Feedback link at the top of the SOS Alert to let us know how we’re doing. You may also leave feedback about the wildfire map via this form.

How does Google decide when to show a wildfire alert?

Wildfire maps are currently limited to large fires in North America. These maps are created when Google launches an SOS Alert for a particular wildfire event, which you can read more about here.

What else should I know about wildfires?

According to, being prepared for a wildfire includes having a preparedness kit ready, identifying local authorities and alerting systems that can offer more real-time information about a fire, and knowing what to do and where to go during an emergency. If you are in the affected area, please look for updates from your local authorities for instruction.

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