118 µg/m³ measured at Walla Walla-12th St, 1 km away, at Aug 06, 9:00AM. The NowCast smoke average is 123 µg/m³ — Unhealthy on the US EPA scale.
Everyone may begin to feel health effects; sensitive groups should avoid prolonged outdoor exertion.
Forecasts show smoke increasing, peaking near 166 µg/m³ within the next 48 hours.
Smoke is likely to persist beyond the next 48 hours.
● 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) | 75 µg/m³ | Aug 06, 5:00PM |
| FireWork (ECCC) | 104 µg/m³ | Aug 06, 4:00PM |
| FireSmoke (UBC BlueSky) | 166 µg/m³ | Aug 06, 5:00PM |
Model values are for the ~10 km grid cell nearest Walla Walla; 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 · 2 nearby monitors
| Model | Typical error | Tendency |
|---|---|---|
| HRRR-Smoke | 31.2 µg/m³ | reads low 22.6 |
| FireSmoke | 69.8 µg/m³ | reads low 69.8 |
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 Walla Walla-12th St — hourly observations, NowCast and both model forecasts.