6 µg/m³ measured at Sf-Usd, 9 km away, at Aug 06, 10:00AM. The NowCast smoke average is 7 µg/m³ — Good on the US EPA scale.
Air quality is good — ideal for outdoor activities.
Forecasts show smoke increasing, peaking near 14 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, 6:00PM |
| FireWork (ECCC) | 11 µg/m³ | Aug 07, 9:00AM |
| FireSmoke (UBC BlueSky) | 7 µg/m³ | Aug 06, 9:00PM |
Model values are for the ~10 km grid cell nearest Sioux Falls; 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 overhead, not in the air you breathe.
● 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 Sf-Usd — hourly observations, NowCast and both model forecasts.