No significant smoke is expected in the next 48 hours.
Air quality is good — ideal for outdoor activities.
1–3 low · 4–6 moderate · 7–10 high · 10+ very high · Forecast squares are Environment Canada's official AQHI period maximums.
Background bands (US EPA AQI, 24-h basis): ■ Good · ■ Moderate
| Model | Peak PM2.5 | Peak around |
|---|---|---|
| FireSmoke (UBC BlueSky) | 0 µg/m³ | Sep 20, 9:00PM |
| FireWork (ECCC) | 8 µg/m³ | Sep 21, 10:00AM |
| HRRR-Smoke (NOAA, 3 km) | 0 µg/m³ | Sep 20, 9:00PM |
Model values are for the nearest forecast grid cell to Thunder Bay; FireSmoke, FireWork and HRRR are independent and often disagree — treat the highest available 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 and HRRR-Smoke estimate the wildfire contribution only, so they read lower than the monitors whenever other sources matter. The optional map plume surfaces are 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; cloud cover is from the model, not observed
Within 150 km, agencies report 2 Out of control · 2 Under control.
No being held fires are reported within 150 km.
Proximity and wind direction do not prove that a fire caused smoke at this location. Sources: BC Wildfire Service in British Columbia; Natural Resources Canada CWFIS elsewhere.
29-day record · 1 nearby monitors
| Model | Typical error | Tendency |
|---|---|---|
| FireWork | 2.6 µg/m³ | reads low 1.3 |
| FireSmoke | 4.8 µg/m³ | reads low 4.8 |
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.
See the Ontario-wide forecast — every monitor, ranked →
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