Johnstown, Pennsylvania, United States Historical Air Quality Analysis
Dive into detailed Air Quality Insights with historical data, monthly patterns, and yearly trends at your fingertips!
October Air Quality Analysis
Johnstown, Pennsylvania, United States
AQI Trends: Highest and Lowest
Same Day Analysis (17th October ):
On this day, AQI across the 5 years varied significantly: 2025 ranks 2nd highest AQI at 30 of Good air quality, showing improvement over 2022 on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 17th Oct - 18th Oct 2025
Johnstown, Pennsylvania, United States
7 AM17th Oct 2025
6 PM
6 AM18th Oct 2025
64AQI
16AQI
59AQI
23AQI
In the last 24 hours,
Johnstown's AQI reached its highest point of 64 at 10 AM during the Day, while the lowest point, 16, was recorded at 7 AM during the Day between 17th Oct and 18th Oct 2025.
Day & Night AQI Trend : Sep - Oct 2025
Johnstown, Pennsylvania, United States
18°C8/28°C
20°C12/28°C
17°C15/20°C
21°C16/26°C
22°C16/29°C
20°C17/23°C
19°C16/25°C
19°C17/23°C
19°C15/26°C
17°C13/23°C
18°C11/28°C
19°C11/26°C
19°C13/28°C
16°C10/25°C
14°C6/25°C
16°C7/25°C
17°C7/28°C
18°C8/29°C
19°C10/29°C
18°C15/25°C
14°C7/16°C
9°C2/15°C
9°C3/18°C
11°C4/21°C
13°C9/18°C
12°C10/14°C
13°C10/17°C
13°C9/17°C
9°C4/17°C
8°C1/18°C
--°C/°C
35AQI
26AQI
32AQI
27AQI
2025 Days Vs Air Quality
Johnstown, Pennsylvania, United States
87%
252
13%
38
Total number of days with different AQI categories in last 291 days in 2025 (74 days remaining)
Under WHO’s Safe Air Quality Limits: 87%
Health Risk Level:
Low
In 2025, 87% of 291 days were within WHO’s safe air quality limits. The risk of health issues is Low, but the long-term effects, especially on vulnerable individuals, remain uncertain.
Annual Air Quality Insights
Johnstown, Pennsylvania, United States
AQI levels in 2025
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
20AQI
21AQI
27AQI
22AQI
31AQI
30AQI
22AQI
27AQI
28AQI
47AQI
52AQI
51AQI
31AQI
25AQI
30AQI
38AQI
46AQI
60AQI
24AQI
25AQI
35AQI
43AQI
50AQI
38AQI
44AQI
30AQI
31AQI
30AQI
28AQI
33AQI
39AQI
25AQI
26AQI
49AQI
32AQI
23AQI
24AQI
25AQI
31AQI
26AQI
29AQI
48AQI
39AQI
24AQI
29AQI
32AQI
25AQI
29AQI
25AQI
30AQI
30AQI
27AQI
37AQI
38AQI
47AQI
36AQI
44AQI
40AQI
26AQI
28AQI
27AQI
33AQI
42AQI
31AQI
23AQI
30AQI
31AQI
28AQI
33AQI
37AQI
30AQI
40AQI
55AQI
54AQI
27AQI
17AQI
23AQI
29AQI
33AQI
16AQI
20AQI
22AQI
19AQI
24AQI
20AQI
24AQI
38AQI
56AQI
53AQI
28AQI
19AQI
31AQI
25AQI
22AQI
28AQI
15AQI
20AQI
14AQI
23AQI
28AQI
32AQI
22AQI
22AQI
34AQI
23AQI
14AQI
22AQI
35AQI
51AQI
21AQI
34AQI
21AQI
26AQI
32AQI
46AQI
20AQI
13AQI
18AQI
31AQI
20AQI
25AQI
25AQI
20AQI
19AQI
22AQI
17AQI
19AQI
27AQI
18AQI
24AQI
37AQI
36AQI
18AQI
17AQI
23AQI
41AQI
28AQI
16AQI
20AQI
21AQI
18AQI
12AQI
12AQI
12AQI
18AQI
23AQI
21AQI
13AQI
18AQI
27AQI
30AQI
19AQI
25AQI
35AQI
59AQI
67AQI
51AQI
46AQI
49AQI
44AQI
44AQI
56AQI
63AQI
69AQI
61AQI
40AQI
20AQI
20AQI
25AQI
27AQI
27AQI
39AQI
43AQI
55AQI
56AQI
57AQI
46AQI
33AQI
27AQI
34AQI
40AQI
33AQI
32AQI
45AQI
58AQI
64AQI
58AQI
50AQI
33AQI
41AQI
43AQI
51AQI
49AQI
39AQI
34AQI
39AQI
39AQI
27AQI
28AQI
34AQI
34AQI
40AQI
56AQI
52AQI
54AQI
53AQI
50AQI
47AQI
46AQI
51AQI
51AQI
54AQI
54AQI
28AQI
42AQI
55AQI
63AQI
74AQI
70AQI
75AQI
59AQI
50AQI
46AQI
41AQI
28AQI
39AQI
56AQI
56AQI
50AQI
24AQI
23AQI
21AQI
16AQI
21AQI
28AQI
33AQI
22AQI
18AQI
22AQI
26AQI
23AQI
22AQI
26AQI
24AQI
24AQI
29AQI
27AQI
44AQI
49AQI
30AQI
22AQI
23AQI
24AQI
26AQI
31AQI
42AQI
47AQI
42AQI
43AQI
37AQI
33AQI
46AQI
41AQI
34AQI
33AQI
27AQI
35AQI
22AQI
28AQI
29AQI
36AQI
39AQI
26AQI
25AQI
20AQI
35AQI
45AQI
43AQI
39AQI
29AQI
17AQI
23AQI
23AQI
32AQI
31AQI
25AQI
24AQI
27AQI
23AQI
30AQI
34AQI
32AQI
31AQI
25AQI
22AQI
43AQI
45AQI
39AQI
33AQI
29AQI
No. of days
202534AQI
Highest AQI recorded in
July45AQI
Lowest AQI recorded in
May22AQI
202432AQI
Highest AQI recorded in
February39AQI
Lowest AQI recorded in
September26AQI
202339AQI
Highest AQI recorded in
June63AQI
Lowest AQI recorded in
October26AQI
202242AQI
Highest AQI recorded in
June51AQI
Lowest AQI recorded in
September34AQI
202141AQI
Highest AQI recorded in
July53AQI
Lowest AQI recorded in
October31AQI
202037AQI
Highest AQI recorded in
November45AQI
Lowest AQI recorded in
March30AQI
Most & Least Polluted Years Over the Last 6 Years
Johnstown's annual 2025 AQI (34) shows an average percentage change of -11.5% (improved AQI) compared to previous years: 2020 (37), 2021 (41), 2022 (42), 2023 (39), 2024 (32).