35 µg/m³ measured at Salem - State Hospital, 2 km away, at Aug 06, 9:00AM. The NowCast smoke average is 36 µg/m³ — Unhealthy for Sensitive Groups on the US EPA scale.
Sensitive groups — children, seniors, and people with heart or lung conditions — should reduce prolonged outdoor exertion.
Forecast concentrations stay near current levels over the next 48 hours.
The current smoke should clear by about Aug 06, 9:00PM.
● Observed · ● FireSmoke · ● FireWork · ● HRRR
Background bands (US EPA AQI, 24-h basis): ■ Good · ■ Moderate · ■ Unhealthy for Sensitive Groups · ■ Unhealthy · ■ Very Unhealthy
| Model | Peak PM2.5 | Peak around |
|---|---|---|
| HRRR-Smoke (NOAA, 3 km) | 34 µg/m³ | Aug 06, 6:00PM |
| FireWork (ECCC) | 20 µg/m³ | Aug 06, 6:00PM |
| FireSmoke (UBC BlueSky) | 8 µg/m³ | Aug 06, 12:00PM |
Model values are for the ~10 km grid cell nearest Salem; the two models are independent and often disagree — treat the higher value as the cautious planning number.
Observations and NowCast are total PM2.5 — wildfire smoke plus every other source — as regulatory monitors measure it, and FireWork models that same total. FireSmoke is a smoke-dispersion model: it estimates the wildfire contribution only, so it reads lower than the monitors whenever other sources matter. The map's optional plume layer is likewise fires-only.
Smoke is at the surface and overhead.
● At the ground · ● Overhead (if mixed down)
Overhead smoke dims the sun but is not what you breathe. The dashed line shows the surface level if the whole column mixed through the boundary layer — a worst case, not a forecast · Data: NOAA HRRR-Smoke
1-day record · 12 nearby monitors
| Model | Typical error | Tendency |
|---|---|---|
| HRRR-Smoke | 21.9 µg/m³ | reads high 9.1 |
| FireWork | 38.6 µg/m³ | reads low 19.5 |
| FireSmoke | 50.6 µg/m³ | reads low 35.8 |
Mean absolute error and average tendency in µg/m³, from forecasts verified 0–6 hours ahead at monitors within 50 km. A short-range record, not a measure of how far ahead a model stays reliable. FireSmoke and HRRR model wildfire smoke only, so they read below the monitors whenever other sources of PM2.5 matter.
Open the live chart for Salem - State Hospital — hourly observations, NowCast and both model forecasts.