Overview: This year began with nearly five months of unusually healthy average Kingston PM2.5 airborne particulate levels. Then the intense western wildfires from June through August turned it into the second-worst of the past six years. With the end of most of those fires, the more northeasterly airflows characteristic of the Atlantic hurricane season brought relatively healthy air to Eastern Ontario for much of the fall and into early winter. But whenever the winds were southerly, they brought with them smoke from up to 500 southern US wildfires. While those fires mostly ended by the beginning of December, between now and next summer the frequently southwesterly airflows will consistently bring toxic emissions from the Texas/Louisiana oil refinery belt. To date in 2025, Kingstonians who did not take measures such as those recommended in our Self-Protection page were exposed to an average of 6.2 µg/m3 fine particulate concentrations from the air they breath. That dangerously exceeds both the 5.0 µg/m3 WHO-recommended limit and the 5.8 µg/m3 threshold beyond which, as you can see on our Health Impacts page, excess mortality begins to soar. It will come as an unwelcome surprise to most Kingstonians that PM2.5 levels have exceeded the WHO limit in 51 of the past 71 months! Do you know others who might benefit from more awareness of the reality of our air quality and how they can better protect their health? If so, please share this link: https://kingstonairquality.ca.
by Ron Hartling
The purpose of this site is to raise awareness of the uncomfortable reality that, with respect to fine particulate matter (PM2.5), Kingston air quality is consistently worse than the World Health Organization (WHO) standard. The site gives practical advice on managing household exposure to health-damaging particulates. Updates are posted daily around 7 am but the satellite view below shows the current Kingston reading at any time of day. If you live elsewhere, just click at your location on the map. For ease of personal decision-making, overall daily risk levels are categorized by severity in the table to the right.
Note that, while most Canadian and US sources define Risk Level 1 as airborne fine-particulate-matter (PM2.5) concentrations less than 12 micrograms per cubic meter (µg/m3), I employ “Level 0” to differentiate readings within the far more evidence-based, less politically-influenced WHO healthy zone. Click on the Health impacts page for clarification on the differences between short- and long-term exposure risks.
Commentary as of Sunday December 7 at 6:45 am
Yesterday’s readings: Yesterday’s Kingston PM2.5 readings were worse than expected, rising over the course of the day through the moderately-unhealthy Level-1 range up to quite-unhealthy Level-2 values by last afternoon, peaking at 19 µg/m3. Our daily average was 10.8 µg/m3, way up from Friday’s 4.3. Overnight readings then plunged to 4 µg/m3.
Forecast for today: Kingston readings are likely to remain at comparatively healthy Level-0 values today and tomorrow.
Detailed forecast: Environment Canada’s 24-hour forecast calls for northeasterly winds this morning, shifting to northwesterly by evening and then full northerly this time tomorrow morning. The nearest fragment of the Jetstream be northwesterly. Eastern Ontario air quality should remain good for as long as the northerly wind directions persist.
Personal protective measures: No such measures should be needed either today or tomorrow.
As of 6 am, this satellite view of PM2.5 fine particulate flows over North America revealed most of the eastern half of the United States covered by a terribly-polluted airmass with Level-2 and Level-3 particulate concentrations. But northwesterly winds are keeping those pollutants mostly south of the border, which is where they belong given that they are primarily poorly-regulated heavy-industry emissions.
Summary of recent readings
This table summarizes and provides context for the most recent three weeks of Kingston PM2.5 airborne fine particulate readings. The key numbers are, of course, the daily averages because that’s what informs us how our recent exposures have contributed to or ameliorated whatever annual exposure to toxic particulates we are comfortable with or accepting of. For those who choose to lower their at-home exposure in order to better protect their and their households’ long-term health, the numbers provide important information on how much effort may be required to stay within their comfort levels.
To facilitate that analysis, the table also computes each day’s risk category (usually a mix of 0’s, 1’s and 2’s), as well as 7- and 28-day running averages and medians. It also reports on the minimum and maximum readings for each day, as well as on the number of hours that day during which Kingston PM2.5 readings may have exceeded either or both the World Health Organization’s recommended maximum and the seriously outdated and therefore misleading US/Canadian equivalent.