Air Quality Warnings in United States

Air Quality Warnings for United States (Northern America) come from National Weather Service (NWS), Federal Emergency Management Agency (FEMA), USGS Earthquake Hazards Program, National Tsunami Warning Center (NOAA). This page explains what these warnings mean, which authority publishes them, and how to check the current status for Washington, D.C..

Check live smog, status for Washington, D.C.Browse all warnings

At a glance

countryUnited States · North America
reference cityWashington, D.C. (38.9, -77.04)
emergencyPrimary emergency number911
risk profilestorm, flood, heat, cold, drought, wildfire, air, earthquake, volcano, tsunami, radiation

What counts as a air quality warnings

Air quality warnings are issued when particulate matter (PM2.5 and PM10), ozone, nitrogen dioxide or sulphur dioxide reach levels that harm health, or when Saharan dust, wildfire smoke or winter smog episodes push concentrations up. Values are usually published as an air quality index, but the index scale and its breakpoints differ from country to country.

Who issues air quality warnings in United States

meteoNational Weather Service (NWS)
civilFederal Emergency Management Agency (FEMA)
seismicUSGS Earthquake Hazards Program
marineNational Tsunami Warning Center (NOAA)

Warning levels, colours and terminology are set nationally. Always read the warning text of the issuing authority: it names the affected districts, the expected time window and the recommended action.

If a warning is active in United States

Ventilate in the early morning on smog days and keep windows shut at peak hours.
Avoid strenuous outdoor exercise when the index is high.
Wear a well-fitted FFP2 or N95 mask if you must be outdoors in smoke or dust.

Where the data comes from

Waarning reads public, key-free sources for United States: Open-Meteo Air Quality, Copernicus CAMS, national environment agencies, national pollen services. Measurements and official warnings are shown separately, and official warnings always keep the name of the authority that issued them.

Frequently asked questions

Who issues air quality warnings in United States?

National Weather Service (NWS), Federal Emergency Management Agency (FEMA), USGS Earthquake Hazards Program, National Tsunami Warning Center (NOAA). Waarning does not issue warnings; it aggregates the public feeds of these bodies and links back to the original source.

What is the emergency number in United States?

The primary emergency number is 911. Use it for a life-threatening situation; for non-urgent reports use the local police station number.

Does Waarning show live air quality warnings for United States?

Yes. The dashboard loads the current values for Washington, D.C. from Open-Meteo Air Quality, Copernicus CAMS, national environment agencies, national pollen services. You can open it with one click and the location is already set.

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Air Quality Warnings in nearby countries

Generated 2026-10-18. Waarning is not an official warning service; in an emergency follow local authorities and emergency services.