WildfireSmokeCanada

Saint John, New Brunswick — Wildfire Smoke Forecast

Live PM2.5, AQHI and 48-hour smoke-model outlook · updated Sep 21, 2:56PM ADT

Current air quality and forecast

Now · observedGood 3 µg/m³ NowCast median across 3 monitors in Saint John and County · range 2–3, highest at Saint John West
Next 48 hoursGood 0–6 µg/m³ · 3 models
Forecast peak6 µg/m³Sep 23, 12:00AM · FireWork

No significant smoke is expected in the next 48 hours.

Air quality is good — ideal for outdoor activities.

AQHI — now & forecast (Environment Canada)

2Now
2Mon
2Mon night
2Tue
2Tue night

1–3 low · 4–6 moderate · 7–10 high · 10+ very high · Forecast squares are Environment Canada's official AQHI period maximums.

Last 24 hours across Saint John and County & next 48 hours forecast

47240now−24 h+24 h+48 hµg/m³
range across monitors

Background bands (US EPA AQI, 24-h basis): Good · Moderate · Unhealthy for Sensitive Groups

Forecast

Next 6 hours
0–3 µg/m³
Peak around Sep 21, 8:00PM
Next 12 hours
0–3 µg/m³
Peak around Sep 21, 8:00PM
Next 24 hours
0–3 µg/m³
Peak around Sep 21, 8:00PM
Next 48 hours
0–6 µg/m³
Peak around Sep 23, 12:00AM
Next 24 hours — model comparison 3 models · 24-hour peak table
ModelPeak PM2.5Peak around
FireSmoke (UBC BlueSky)0 µg/m³Sep 21, 4:00PM
FireWork (ECCC)3 µg/m³Sep 21, 8:00PM
HRRR-Smoke (NOAA, 3 km)0 µg/m³Sep 21, 4:00PM

Model values are for the nearest forecast grid cell to Saint John; 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.

Sky vs. ground

Little smoke at the surface or overhead.

Sky right now
Clear sky

At the ground · Overhead (if mixed down)

010203:00PM9:00PM3:00AMµg/m³

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

Nearby fires

150 km radius

Fire snapshot updated 2026-09-21 17:55 UTC

No active incidents are reported within 150 km.

Out of control0 fires

No out of control fires are reported within 150 km.

Being held0 fires

No being held fires are reported within 150 km.

Under control0 fires

No under control 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.

Forecast track record here

29-day record · 3 nearby monitors

ModelTypical errorTendency
FireWork2.0 µg/m³reads low 1.3
FireSmoke4.0 µg/m³reads low 4.0

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.

Monitors in Saint John and County

See the New Brunswick-wide forecast — every monitor, ranked →

More in New Brunswick: Fredericton · Moncton · Edmundston