Red flag warning
A red flag warning means fire weather is happening now or within the next day: strong wind, very low humidity and dry vegetation that let any new fire spread fast.
Active red flag warnings and fire weather watches
What a red flag warning means
The National Weather Service issues a red flag warning when the combination of warm temperatures, very low relative humidity and strong winds is occurring or about to occur, and vegetation is dry enough to burn easily. It doesn't mean there is a fire — it means a fire that starts will be hard to control. The exact thresholds are set by each NWS office for its own area, because fuels and climate differ.
Red flag warning vs fire weather watch
A fire weather watch comes first: critical fire weather is possible in the next 12 to 72 hours. A red flag warning is the upgrade: critical conditions are occurring or expected very soon, usually within a day.
What to do during a red flag warning
- Don't do anything outdoors that makes sparks or flame: no burning debris, no campfires, no mowing dry grass, no chains dragging from trailers.
- Park only on pavement or gravel — a hot exhaust can ignite dry grass.
- Check your county's burn restrictions; many ban all outdoor burning during warnings.
- If you live near wildland, have your go-bag ready and your car fueled (see the evacuation checklist).
- Report any smoke or fire to 911 immediately.
Source: National Weather Service fire weather program (weather.gov/fire).
Questions
How long does a red flag warning last?
It's issued for a specific time window — often an afternoon and evening, sometimes several days during long wind events. The end time is shown on each alert above.
Can I have a campfire during a red flag warning?
You shouldn't, and in many places it is illegal: most counties and land agencies ban open flames when a red flag warning is in effect.
Does a red flag warning mean there is a fire?
No. It is a weather warning about how easily fires could start and spread, not a report of an existing fire. Active fires are on the wildfire map.
Get alerts before the smoke arrives
Wildfire Tracker for iPhone: fires near your saved places, containment, wind direction and air quality — with alerts only for fires that are actually active. Free, no account.