Air Quality
Excellent
No health implications.
6
PM2.5
11
PM10
7
O3
0.4
CO
7
SO2
24
NO2
No health implications.
Advise
Everyone can continue their outdoor activities normally.
Air Quality
Today
21 May
20
Excellent
Fri
22 May
41
Excellent
Sat
23 May
49
Excellent
Sun
24 May
44
Excellent
Mon
25 May
51
Good
Tue
26 May
15
Excellent
Wed
27 May
32
Excellent
Air quality in the last 12 months (Cheung Chau)
|
2026/04
|
26
|
39
|
59
|
26
|
40
|
62
|
59
|
50
|
44
|
44
|
48
|
48
|
41
|
42
|
35
|
36
|
35
|
44
|
47
|
50
|
40
|
38
|
18
|
24
|
48
|
57
|
47
|
39
|
26
|
26
|
|
|
2026/03
|
21
|
20
|
17
|
21
|
28
|
27
|
46
|
58
|
41
|
19
|
37
|
46
|
61
|
56
|
57
|
53
|
47
|
49
|
42
|
60
|
37
|
50
|
50
|
69
|
70
|
66
|
54
|
48
|
49
|
37
|
38
|
|
2026/02
|
33
|
48
|
61
|
69
|
71
|
66
|
34
|
30
|
44
|
51
|
29
|
29
|
48
|
60
|
55
|
40
|
39
|
35
|
46
|
56
|
65
|
57
|
45
|
48
|
37
|
59
|
31
|
23
|
|||
|
2026/01
|
50
|
34
|
39
|
56
|
43
|
42
|
51
|
57
|
58
|
68
|
61
|
63
|
73
|
75
|
78
|
82
|
80
|
78
|
75
|
55
|
33
|
33
|
35
|
56
|
65
|
68
|
47
|
53
|
60
|
52
|
30
|
|
2025/12
|
47
|
48
|
77
|
80
|
76
|
82
|
84
|
79
|
69
|
66
|
72
|
66
|
37
|
52
|
58
|
59
|
53
|
59
|
67
|
70
|
62
|
71
|
74
|
50
|
42
|
51
|
59
|
63
|
61
|
62
|
58
|
|
2025/11
|
41
|
42
|
30
|
20
|
27
|
40
|
33
|
30
|
23
|
23
|
23
|
44
|
43
|
41
|
54
|
53
|
54
|
41
|
40
|
44
|
52
|
52
|
60
|
63
|
53
|
65
|
65
|
74
|
68
|
58
|
|
|
2025/10
|
55
|
38
|
38
|
45
|
25
|
21
|
31
|
51
|
42
|
54
|
58
|
45
|
32
|
32
|
38
|
42
|
54
|
54
|
30
|
23
|
21
|
27
|
32
|
46
|
50
|
52
|
46
|
45
|
54
|
59
|
42
|
|
2025/09
|
36
|
37
|
49
|
57
|
50
|
48
|
46
|
19
|
24
|
26
|
26
|
38
|
44
|
47
|
44
|
32
|
38
|
45
|
43
|
41
|
24
|
23
|
26
|
20
|
19
|
26
|
39
|
39
|
39
|
45
|
|
|
2025/08
|
33
|
34
|
30
|
36
|
28
|
27
|
28
|
31
|
49
|
54
|
57
|
54
|
48
|
46
|
22
|
29
|
35
|
19
|
22
|
27
|
27
|
38
|
41
|
34
|
27
|
33
|
50
|
34
|
36
|
27
|
37
|
|
2025/07
|
23
|
25
|
33
|
45
|
51
|
40
|
50
|
35
|
45
|
37
|
34
|
29
|
34
|
43
|
37
|
43
|
45
|
53
|
34
|
27
|
18
|
20
|
23
|
26
|
42
|
46
|
47
|
56
|
46
|
39
|
34
|
|
2025/06
|
41
|
39
|
27
|
42
|
49
|
40
|
37
|
32
|
45
|
26
|
24
|
19
|
18
|
19
|
24
|
23
|
21
|
24
|
25
|
21
|
24
|
24
|
29
|
32
|
36
|
30
|
22
|
25
|
27
|
23
|
|
|
2025/05
|
35
|
45
|
43
|
34
|
33
|
31
|
23
|
32
|
23
|
43
|
45
|
55
|
58
|
51
|
39
|
34
|
25
|
28
|
30
|
35
|
38
|
41
|
44
|
30
|
51
|
43
|
56
|
56
|
24
|
27
|
32
|
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
9
|
10
|
11
|
12
|
13
|
14
|
15
|
16
|
17
|
18
|
19
|
20
|
21
|
22
|
23
|
24
|
25
|
26
|
27
|
28
|
29
|
30
|
31
|
- Excellent
- Good
- Lightly
- Moderately
- Heavily
- Severely
Air quality source: CNEMC
*: primary pollution