Overview: From the perspective of pollution from toxic fine particulate matter (PM2.5), Eastern Ontario’s air quality for the first six months of 2026 remained within the hazard zone (5.8 µg/m3). That is 16% above the WHO-recommended limit of 5.0 µg/m3 and, as you can see from the chart on our Health Impacts page, has crossed the threshold for causing increased mortality among Kingstonians. Kingston’s PM2.5 levels had exceeded that limit in 56 of the past 78 months, often much worse. More northerly wind directions in April and May kept south of the border some of the US industrial emissions which constitute most of Eastern Ontario’s air pollution, but that pollution returned in June with the reversion to mostly southwesterly airflows. Northern Canada’s wildfire season got off to a late start at the end of June and the resulting smoke plumes had yet to reach Eastern Ontario by Canada Day. That can be expected to change for the worse, with northern smoke plumes arriving from what may well be one of the worst wildfire seasons on record. What we can also expect, once Canadian wildfire smoke arrives over US cities, is for a repeat performance of hypocritical American legislators holding press conferences on pressuring Canada to do a better job of combatting wildfires, totally ignoring the fact that Canadians’ annual exposure to US industrial emissions vastly exceeds what they get from our wildfires, not to mention the reality that their refusal to adhere to global restrictions on the carbon emissions which are the root cause of those fires. Given that we have absolutely no levers to influence US-generated pollution, all we can do is to limit how much gets into our lungs by taking some of the measures suggested in our Self-Protection page. 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 critical differences between short- and long-term exposure risks.
Commentary as of Thursday July 16 at 7:00 am
Yesterday’s readings: Kingston’s official PM2.5 readings yesterday were the worst of the year to date, gradually declining from a highly-toxic 122 µg/m3 at midnight to a still-quite unhealthy 23 µg/m3 by late evening. Our daily average was 41.8 µg/m3, by far the worst of the year to date. Overnight readings ranged from 24 to 31 µg/m3 but jumped to 53 at 6 am.
Forecast for today: The big picture today can best be seen in Environment Canada 24-Hour Average Smoke Plume map, which shows the worst particulate concentrations over the Great Lakes and approaching to our northeast. We’re already at the higher end of the Level-3 risk category and it’s likely to get worse as the day unfolds. Updates: 86 µg/m3 at 7 am; 133 at 8 am; 165 at 9 am; 176 at 10 am; peaked at a Level-6 178 at 11 am before falling back to a still-unhealthy for all, Level-4, 63 by 4 pm.
Detailed forecast: Environment Canada’s 24-hour Kingston forecast calls for sometimes gusty northwesterly winds continuing for the rest of today, becoming full northerly overnight. That’s consistent with the high-altitude Jetstream which will be passing directly overhead. The UBC Firesmoke model predicts that Eastern Ontario air quality will continue to worsen over the course of today, perhaps moderating this evening as the worst of the plume passes to our south and more northerly winds kick in. In a switch from thus far in 2026 wildfire season, there are now only a handful of fires burning in the USA. Canada’s 106 wildfires are now evenly split between the West and Northern Ontario, the latter more heavily impacting Eastern Ontario due to proximity.
Personal protective measures: If at all possible, it would be wise to keep your windows and doors closed and any ideally-HEPA-grade filters running on full for at least the next 24 hours. I strongly recommend wearing an N95 mask whenever you are outdoors.
While this 6 am satellite view of PM2.5 fine particulate flows over North America again painted a dismal picture of moderate to severely unhealthy airborne pollutants blanketing much of the continent, it’s indirect algorithm seriously underestimating the severity of the actual ground readings in the areas covered by wildfire smoke plumes as opposed to industrial pollution. Sault Ste. Marie was shown as only 12 µg/m3 whereas its ground station was reporting an outright hazardous 414 µg/m3!
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.