GuideNational Weather Service
Warning, watch or advisory? What the NWS levels mean
A warning means act now, a watch means be ready, and an advisory means take care. The National Weather Service issued 39,904 warnings, 3,857 watches and 19,541 advisories in 2025, counted by event in the Iowa Environmental Mesonet's archive of NWS products.
By AreaZine · Updated · written with AI tools and checked against the agencies' records (editorial policy)
The three levels, and how many of each
| Level | What it asks of you | Issued in 2025 | Most common |
|---|---|---|---|
| Warning | The hazard is happening, about to happen or very likely: act now. | 39,904 | Severe Thunderstorm Warning (23,433), Flash Flood Warning (5,219), Flood Warning (4,230), Tornado Warning (3,014), Red Flag Warning (957) |
| Watch | The conditions for the hazard are possible: be ready to act. | 3,857 | Flood Watch (1,044), Winter Storm Watch (626), Fire Weather Watch (576), Severe Thunderstorm Watch (448), High Wind Watch (434) |
| Advisory | A less serious hazard that can still cause harm: take care. | 19,541 | Flood Advisory (10,035), Winter Weather Advisory (2,099), Dense Fog Advisory (1,882), Wind Advisory (1,816), Heat Advisory (962) |
Source: Iowa Environmental Mesonet archive of NWS watches, warnings and advisories; NWS directives.
Warning: act now
A warning is issued when a hazard is occurring, imminent or very likely and threatens life or property. Short warnings for storms (tornado, severe thunderstorm, flash flood, special marine) are drawn as polygons around the storm's path and usually last under an hour; longer ones (winter storm, extreme heat, high wind, red flag) cover counties or forecast zones for a day or more.
Watch: be ready
A watch means the ingredients for the hazard are in place or expected, but it is not yet happening. Tornado and severe thunderstorm watches come from the Storm Prediction Center and cover large areas for several hours; local offices issue watches for floods, winter storms, fire weather, heat and wind. A watch often, but not always, comes before a warning.
Advisory: take care
An advisory is for weather that is a nuisance or a danger if you are careless, below warning thresholds: wind advisories, winter weather advisories, heat advisories, dense fog advisories. Each office sets most thresholds for its area with local partners.
Statements, and the colours on maps
A statement (special weather statement, hydrologic statement) passes on information without a formal level; AreaZine does not count or publish them. The colours on NWS hazard maps are fixed per product, not per level: two warnings can have different colours.
How you are alerted
Only some warnings reach phones as Wireless Emergency Alerts: among them tornado and extreme wind warnings, flash flood warnings the NWS tags "considerable" or "catastrophic", and severe thunderstorm warnings tagged "destructive"; most warnings do not (the NWS page on phone alerts). NOAA Weather Radio carries every warning for its area. AreaZine is a record of what was issued; it is not a way to receive warnings.