wildfiresmoke.app independently compares live US air-quality measurements against the operational wildfire-smoke forecast models — every hour, at every station. Forecast pages and maps exist elsewhere; the point here is showing observations and the models side by side so you can judge how much to trust the forecast where you live.
Hourly PM2.5 from 1285 federal, state, local and tribal regulatory monitors, aggregated via the AirNow data exchange run by the US EPA with NOAA, the National Park Service, NASA, tribal, state and local agencies. Real-time data is not final-verified: agencies may correct values later. Timestamps mark the end of each measurement hour. Each monitor is assigned to its state, which supplies the timezone its times are shown in.
Each model is sampled at the grid cell nearest each station (and each city page's coordinates), and a station is kept if any model or the monitor itself has something to say about it. The map can drape and animate either model's smoke as a colored surface — HRRR's near-surface smoke (next-48-hour maximum plus an hourly animation) or FireWork's wildfire smoke plume (3-hourly animation), one at a time. FireWork's plume field is the fires' contribution only, so clean-air regions stay blank; ECCC open data, reproduced with attribution.
The map can animate 10-meter surface wind from HRRR (3 km grid), sampled for the current hour and resampled to a regular grid; flowing particles are drawn with leaflet-velocity (CSIRO). Surface wind indicates near-ground drift — smoke frequently travels at higher altitudes on different headings, so treat it as context, not a plume trajectory.
NowCast is the US EPA's smoke-responsive weighted average of recent hourly readings; the colored chart bands are US EPA AQI category thresholds (24-hour basis, 2024 revision) and apply to NowCast, not single hours. This site publishes no health index of its own.
Active US incidents and their mapped perimeters come from NIFC's Wildland Fire Interagency Geospatial Services, refreshed hourly. Canadian fires are shown too, from the Canadian Wildland Fire Information System, Natural Resources Canada — smoke crosses the border regularly, and a fire in British Columbia or Ontario is often the reason for a bad air day in the northern states. A separate layer shows satellite fire detections from the last 24 hours, which flag heat signatures rather than confirmed fires.
Every hour, each model's earlier forecasts are matched against what stations actually measured, and the errors are logged per station, per model and per forecast run. The AI-written national outlook draws only on these measured values and model outputs — it is generated from structured facts, validated, and clearly labeled.
Observations, indices and pages refresh hourly. Model runs arrive on their own schedules (HRRR hourly, FireWork 2×/day, FireSmoke 4×/day); the freshness panel on the dashboard shows the age of every input.
Independently built. Source data belongs to the agencies above. Questions, corrections or data issues: contact@wildfiresmoke.ca. Site last generated Aug 06, 2026, 12:45PM.