Air quality
Air quality in Chatham, ON today
Updated
Good (US AQI 27) Air quality is satisfactory and poses little or no risk; a good time for outdoor activity. Model estimate for Thu, Nov 5, 9:00 pm (02:00 UTC).
Air quality in Chatham, ON right now
Right now the modelled US Air Quality Index for Chatham, Ontario, Canada is 27, which falls in the "Good" band (up to 50). Air quality is satisfactory and poses little or no risk; a good time for outdoor activity.
The index is driven mainly by ozone, whose own sub-index is 27. Ozone usually peaks in the afternoon on sunny days and falls back after sunset.
PM2.5 is 3.2 µg/m³, within the WHO 24-hour guideline of 15 µg/m³; PM10 is 3.3 µg/m³ against a guideline of 45; ozone is 44 µg/m³ (below the WHO 8-hour level of 100); nitrogen dioxide is 12 µg/m³ (below the 24-hour guideline of 25).
Also this hour: carbon monoxide 173 µg/m³.
Live AQI, PM2.5, PM10 and ozone for Chatham, Ontario, Canada, with a 48-hour forecast and the best time to be outside.
- US AQI now
- 27 Good
- PM2.5
- 3.2 µg/m³ 0.2× WHO 24-h guideline
- PM10
- 3.3 µg/m³
- Ozone
- 44 µg/m³
- Dominant pollutant
- ozone sub-index 27
- Best hour tomorrow
- 6:00 am AQI 18
- European AQI
- 22
Chatham, ON AQI forecast: next 48 hours
Over the next 24 hours the AQI is forecast to range from 18 around Fri 6:00 am to 27 around Thu 9:00 pm, staying "Good" throughout.
The following day looks similar, averaging about 28.
| Local time (America/Toronto) | US AQI | Category | PM2.5 µg/m³ | PM10 µg/m³ | Ozone µg/m³ |
|---|---|---|---|---|---|
| Thu 9:00 pm | 27 | Good | 3.2 | 3 | 44 |
| Fri 12:00 am | 23 | Good | 3.6 | 4 | 33 |
| Fri 3:00 am | 20 | Good | 3.3 | 3 | 39 |
| Fri 6:00 am | 18 | Good | 0.4 | 0 | 53 |
| Fri 9:00 am | 21 | Good | 0.5 | 1 | 59 |
| Fri 12:00 pm | 26 | Good | 0.7 | 1 | 60 |
| Fri 3:00 pm | 27 | Good | 0.6 | 1 | 58 |
| Fri 6:00 pm | 27 | Good | 0.5 | 1 | 59 |
| Fri 9:00 pm | 27 | Good | 0.5 | 1 | 63 |
| Sat 12:00 am | 28 | Good | 0.5 | 1 | 64 |
| Sat 3:00 am | 29 | Good | 0.4 | 0 | 63 |
| Sat 6:00 am | 29 | Good | 0.4 | 0 | 59 |
| Sat 9:00 am | 28 | Good | 0.6 | 1 | 56 |
| Sat 12:00 pm | 27 | Good | 0.9 | 1 | 57 |
| Sat 3:00 pm | 26 | Good | 1.4 | 2 | 56 |
| Sat 6:00 pm | 26 | Good | 1.6 | 2 | 52 |
| Sat 9:00 pm | 25 | Good | 1.5 | 2 | 53 |
Every third hour of the CAMS forecast via Open-Meteo. US AQI uses rolling averages (24 h for particles, 8 h for ozone), so it moves more slowly than the hourly concentrations.
Best time to be outside in Chatham, ON tomorrow
Between 6 am and 9 pm local time, the cleanest air tomorrow is forecast around 6:00 am (AQI 18, Good) and the worst around 2:00 pm (AQI 27). The difference across the day is small, so timing matters little.
Chatham, ON vs the rest of Canada
Across 9 Canada cities we track, the average US AQI right now is 60 (Moderate). Chatham, ON at 27 is 33 points cleaner than average.
For context, the median across 241 cities worldwide is 49.
Air quality in cities near Chatham, ON
| City | Distance | US AQI | Category | PM2.5 µg/m³ |
|---|---|---|---|---|
| St. Thomas | 92 km | 27 | Good | 3.4 |
Model vs measured
We found no measured PM2.5 sensor cell within 25 km of Chatham, ON, so the numbers on this page are model estimates. Models capture regional pollution well but can miss very local sources such as a busy road or a nearby fire.
Advice for sensitive groups
With the AQI at 27, there is no need for sensitive groups to change plans. People with asthma should still carry their reliever inhaler as usual.
What the US AQI numbers mean
| US AQI | Category | What it means |
|---|---|---|
| 0-50 | Good | Air quality is satisfactory and poses little or no risk; a good time for outdoor activity. |
| 51-100 | Moderate | Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors. |
| 101-150 | Unhealthy for Sensitive Groups | People with heart or lung disease, older adults, children and teens should cut back on prolonged or heavy exertion outdoors. |
| 151-200 | Unhealthy | Everyone should reduce prolonged or heavy exertion outdoors; sensitive groups should avoid it and keep windows closed. |
| 201-300 | Very Unhealthy | Health alert: everyone should avoid prolonged or heavy exertion outdoors, and sensitive groups should stay indoors. |
| 301-500 | Hazardous | Emergency conditions: everyone should avoid all outdoor physical activity and stay indoors with filtered air if possible. The scale tops out at 500; heavier dust or smoke is shown as 500. |
Values on this page are modelled by CAMS (Copernicus) and served by Open-Meteo; they are estimates for the area around the city centre, not readings from an official monitor.
Nearby cities
More for Chatham
Air quality elsewhere
Guides
Data: Open-Meteo Air Quality API, Copernicus Atmosphere Monitoring Service (CAMS).