Smog in Markham — Live Data: AQI, Fine Dust, Wind, UV and Health Advice

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Latest air quality data: Markham
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Pollution and air quality forecast for Markham. Today is Thursday, August 27, 2026. The following air pollution values have been recorded for Markham:
  1. particulate matter (PM2.5) dust - 5 (Good)
  2. particulate matter (PM10) suspended dust - 5 (Good)
  3. ozone (O3) - 89 (Moderate)
  4. nitrogen dioxide (NO2) - 18 (Good)
  5. sulfur dioxide (SO2) - 5 (Good)
  6. carbon monoxide (CO) - 342 (Good)
Real-time Air Quality Index (AQI) for Markham, Wednesday, August 26, 2026: 2.

air quality index: 1
AQI 2 Moderate

What is the air quality in Markham today? Is the air polluted in Markham?. Is there smog?

Today (Wednesday, August 26, 2026) air quality is moderate in Markham. Some pollutants in Markham may slightly affect very few hypersensitive individuals. Air pollutants in Markham may cause minor breathing discomfort to sensitive people.


What is the current level of PM2.5 in Markham? (particulate matter (PM2.5) dust)
Today's PM2.5 level is: 5 (Good) For comparison, the highest level of PM2.5 in Markham in the last 7 days was: 9 (Wednesday, August 26, 2026) and the lowest: 3 (Monday, August 24, 2026).

What is the level of PM10 today in Markham? (particulate matter (PM10) suspended dust)
The current level of particulate matter PM10 in Markham is: 5 (Good)

How is the O3 level today in Markham? (ozone (O3))
89 (Moderate)

How high is the level of NO2? (nitrogen dioxide (NO2))
18 (Good)

What is the level of SO2 pollution? (sulfur dioxide (SO2))
5 (Good)

How high is the CO level? (carbon monoxide (CO))
342 (Good)



Current data Wednesday, August 26, 2026 at 9:00 PM

PM2,5 5 (Good)

PM10 5 (Good)

O3 89 (Moderate)

NO2 18 (Good)

SO2 5 (Good)

CO 342 (Good)

Data on air pollution from recent days in Markham

index 2026-08-26 2026-08-25 2026-08-24 2026-08-23 2026-08-22 2026-08-21 2026-08-20 2026-08-19
pm25 9
Good		 5
Good		 3
Good		 3
Good		 4
Good		 4
Good		 4
Good		 7
Good
pm10 9
Good		 5
Good		 3
Good		 3
Good		 4
Good		 4
Good		 4
Good		 7
Good
o3 61
Good		 55
Good		 46
Good		 58
Good		 89
Moderate		 68
Good		 58
Good		 70
Moderate
no2 20
Good		 7
Good		 7
Good		 6
Good		 7
Good		 10
Good		 10
Good		 10
Good
so2 5
Good		 1
Good		 2
Good		 2
Good		 3
Good		 3
Good		 2
Good		 3
Good
co 269
Good		 172
Good		 155
Good		 162
Good		 182
Good		 195
Good		 178
Good		 194
Good
data source »

Markham

Wednesday, August 26, 2026 at 9:00 PM

PM2,5 5.2 (Good)

particulate matter (PM2.5) dust

PM10 5.2 (Good)

particulate matter (PM10) suspended dust

O3 89 (Moderate)

ozone (O3)

NO2 18 (Good)

nitrogen dioxide (NO2)

SO2 5.4 (Good)

sulfur dioxide (SO2)

CO 342 (Good)

carbon monoxide (CO)

Markham

index 2026-08-19 2026-08-20 2026-08-21 2026-08-22 2026-08-23 2026-08-24 2026-08-25 2026-08-26
pm25 6.9 4.1 3.8 4.4 2.8 3.4 4.5 9.4
pm10 7.1 4.2 3.9 4.5 2.9 3.4 4.6 9.4
o3 70 58 68 89 58 46 55 61
no2 9.8 9.6 10 7.1 6.3 7 6.6 20
so2 2.6 1.8 2.6 2.8 1.9 2.1 1.4 5
co 194 178 195 182 162 155 172 269

* Pollution data source: https://openaq.org () The data is licensed under CC-By 4.0

🌦️ Weather · 16-day Forecast — Markham

🌦️ WEATHER · 16-DAY FORECASTMarkham🌧️18°RainToday · ↑19° ↓14°💨 5 km/h · 💧 80%Mon24.08🌧️19°14°Tue25.08☀️23°16°Wed26.08☁️28°17°Thu27.08🌧️25°18°Fri28.08☀️21°14°Sat29.08☁️23°12°Sun30.08🌧️23°18°Mon31.08🌧️26°21°Tue1.09🌧️29°19°Wed2.09🌤️28°17°Thu3.09🌧️27°19°Fri4.09🌧️33°19°Sat5.09🌧️34°22°Sun6.09🌧️29°20°Mon7.09🌧️26°20°Tue8.09🌧️30°20°pollution-alert.com · August 27, 2026

16-day weather forecast for Markham: today around 19°C (rain), lows near 14°C. Daily temperature and conditions, updated every day. Strong wind (about 20 km/h) is actively clearing smog and dust away.

☀️ UV Index · 16-day Forecast — Markham

☀️ UV INDEX · 16-DAY FORECASTMarkham03681111+5.6UV MODERATEtoday, day maxSeek shade around midday. SPF 30+, sunglasses and ahat for longer stays.⏱ Unprotected fair skin can burn in about 35 min6Wed26.086Thu27.086Fri28.086Sat29.083Sun30.084Mon31.085Tue1.096Wed2.096Thu3.096Fri4.096Sat5.096Sun6.096Mon7.095Tue8.092Wed9.096Thu10.090-2 low3-5 moderate6-7 high8-10 very high11+ extremepollution-alert.com · August 27, 2026

The UV index in Markham today is 5.6 (moderate) — unprotected fair skin can burn in about 35 minutes.

📍 Air quality in nearby cities

Live PM2.5 around Markham — compare nearby locations.

Frequently asked questions

Is the air safe to breathe in Markham today?
The current average PM2.5 across Markham is about 5 µg/m³, rated “Good”. Air quality is good — outdoor activities are fine for everyone.
What is the current PM2.5 level in Markham?
Right now PM2.5 in Markham averages about 5 µg/m³ (“Good”). PM2.5 are fine particles small enough to reach the lungs and bloodstream.
Which day last week had the worst air in Markham?
Over the past week, the highest daily PM2.5 in Markham was recorded on Wednesday, August 26 (about 9 µg/m³).
What is the UV index in Markham today?
The UV index in Markham today is 5.6 (moderate) — unprotected fair skin can burn in about 35 minutes.
Does today's wind help disperse smog in Markham?
Strong wind (about 20 km/h) is actively clearing smog and dust away.
How is air quality measured?
Air quality here is based on PM2.5 — the concentration of fine particulate matter in µg/m³. Lower values mean cleaner air. Data is updated daily from Open-Meteo.