Below the WHO 24-hour guideline on 89% of days — 21 elevated periods rose above it. Scroll or pinch to zoom; zoom in past three weeks to see hour-by-hour readings.
Annual averages: Downtown 8.2, West 7.7, Mountain 7.6 µg/m³ — all below Canada’s annual standard (8.8) and all above the WHO annual guideline (5).
A station-day average is shown only when that station reported at least 18 of 24 hours
(75% completeness rule); gaps are left blank, never interpolated. Hourly view shows the
raw published readings.
*The Canadian standard (CAAQS 2020) is assessed as the 3-year average of each year’s
98th-percentile daily value — individual days above the line do not, on their own,
mean the standard was exceeded.
Data: Air Quality Ontario (Ontario Ministry of the Environment), hourly PM2.5 —
automatically polled, not final-verified. Stations 29000 Downtown, 29118 West,
29214 Mountain. Retrieved 2026-07-06.
All values, dates and labels on this page were generated programmatically from the
source data (make_viewer.py).