18 µg/m³ measured at Yreka, 1 km away, at Aug 06, 9:00AM. The NowCast smoke average is 16 µg/m³ — Moderate on the US EPA scale.
Unusually sensitive people should consider reducing prolonged outdoor exertion.
Forecasts show smoke increasing, peaking near 30 µg/m³ within the next 48 hours.
No significant smoke is expected in the next 48 hours.
● Observed · ● FireSmoke · ● FireWork · ● HRRR
Background bands (US EPA AQI, 24-h basis): ■ Good · ■ Moderate
| Model | Peak PM2.5 | Peak around |
|---|---|---|
| HRRR-Smoke (NOAA, 3 km) | 7 µg/m³ | Aug 06, 11:00AM |
| FireWork (ECCC) | 30 µg/m³ | Aug 07, 10:00AM |
| FireSmoke (UBC BlueSky) | 9 µg/m³ | Aug 06, 11:00AM |
Model values are for the ~10 km grid cell nearest Yreka; 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.
Little smoke at the surface or 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
Open the live chart for Yreka — hourly observations, NowCast and both model forecasts.