LIVE • 2026-05-27

Highest O3 cities right now

Top 30 cities ranked by current O3 concentration across all 217 tracked locations. Refreshes every 30 minutes. The highest O3 right now is in Chennai, India at 173.0 ppb. WHO 2021 8-hour guideline: 100 μg/m³ (~50 ppb).

#1
173.0 ppb

IN

Chennai

157
AQI
PM2.5
31.9μg
PM10
38.4μg
O3
173.0ppb
Unhealthy
#2
157.0 ppb

IR

Tehran

111
AQI
PM2.5
7.2μg
PM10
11.6μg
O3
157.0ppb
Unhealthy for Sensitive Groups
#3
152.0 ppb

IN

Kanpur

290
AQI
PM2.5
100.8μg
PM10
577.4μg
O3
152.0ppb
Very Unhealthy
#4
146.0 ppb

FR

Paris

57
AQI
PM2.5
9.7μg
PM10
20.4μg
O3
146.0ppb
Moderate
#5
145.0 ppb

OM

Muscat

93
AQI
PM2.5
39.3μg
PM10
78.5μg
O3
145.0ppb
Moderate
#6
144.0 ppb

PK

Lahore

166
AQI
PM2.5
19.2μg
PM10
34.5μg
O3
144.0ppb
Unhealthy
#7
141.0 ppb

IT

Milan

52
AQI
PM2.5
11.5μg
PM10
19.4μg
O3
141.0ppb
Moderate
#8
136.0 ppb

IN

Lucknow

191
AQI
PM2.5
52.9μg
PM10
137.4μg
O3
136.0ppb
Unhealthy
#9
135.0 ppb

IT

Rome

46
AQI
PM2.5
8.9μg
PM10
14.5μg
O3
135.0ppb
Good
#10
135.0 ppb

AE

Dubai

156
AQI
PM2.5
52.9μg
PM10
94.3μg
O3
135.0ppb
Unhealthy
#11
134.0 ppb

QA

Doha

151
AQI
PM2.5
50.3μg
PM10
177.4μg
O3
134.0ppb
Unhealthy
#12
131.0 ppb

PT

Lisbon

56
AQI
PM2.5
15.9μg
PM10
24.6μg
O3
131.0ppb
Moderate
#13
130.0 ppb

NP

Pokhara

110
AQI
PM2.5
9.5μg
PM10
17.2μg
O3
130.0ppb
Unhealthy for Sensitive Groups
#14
127.0 ppb

EG

Cairo

62
AQI
PM2.5
16.5μg
PM10
19.8μg
O3
127.0ppb
Moderate
#15
127.0 ppb

BR

Rio de Janeiro

58
AQI
PM2.5
21.1μg
PM10
21.8μg
O3
127.0ppb
Moderate
#16
125.0 ppb

AF

Kabul

121
AQI
PM2.5
15.1μg
PM10
36.3μg
O3
125.0ppb
Unhealthy for Sensitive Groups
#17
124.0 ppb

AE

Abu Dhabi

139
AQI
PM2.5
44.4μg
PM10
87.3μg
O3
124.0ppb
Unhealthy for Sensitive Groups
#18
123.0 ppb

IN

Pune

69
AQI
PM2.5
14.1μg
PM10
17.3μg
O3
123.0ppb
Moderate
#19
122.0 ppb

DE

Munich

46
AQI
PM2.5
6.9μg
PM10
13.3μg
O3
122.0ppb
Good
#20
122.0 ppb

BR

Belo Horizonte

56
AQI
PM2.5
12.6μg
PM10
13.1μg
O3
122.0ppb
Moderate
#21
121.0 ppb

BA

Sarajevo

76
AQI
PM2.5
33.2μg
PM10
35.4μg
O3
121.0ppb
Moderate
#22
120.0 ppb

AT

Vienna

47
AQI
PM2.5
8.3μg
PM10
18.2μg
O3
120.0ppb
Good
#23
120.0 ppb

SK

Bratislava

48
AQI
PM2.5
8.2μg
PM10
17.8μg
O3
120.0ppb
Good
#24
119.0 ppb

JO

Amman

60
AQI
PM2.5
16.1μg
PM10
31.3μg
O3
119.0ppb
Moderate
#25
117.0 ppb

DZ

Algiers

53
AQI
PM2.5
11.1μg
PM10
20.1μg
O3
117.0ppb
Moderate
#26
116.0 ppb

HU

Budapest

44
AQI
PM2.5
10.7μg
PM10
21.3μg
O3
116.0ppb
Good
#27
116.0 ppb

AO

Luanda

68
AQI
PM2.5
18.6μg
PM10
24.9μg
O3
116.0ppb
Moderate
#28
115.0 ppb

GB

London

58
AQI
PM2.5
12.7μg
PM10
24.5μg
O3
115.0ppb
Moderate
#29
115.0 ppb

BE

Brussels

57
AQI
PM2.5
8.6μg
PM10
20.3μg
O3
115.0ppb
Moderate
#30
113.0 ppb

LB

Beirut

90
AQI
PM2.5
24.1μg
PM10
29.7μg
O3
113.0ppb
Moderate

About O3

See the full O3 guide for sources, health effects, and mitigation. Or jump back to overall most polluted cities ranked by US EPA Air Quality Index.

See also: highest PM2.5 · highest PM10 · highest NO2