Fontana, California, 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
Fontana, California, United States
AQI Trends: Highest and Lowest
Same Day Analysis (19th October ):
On this day, AQI across the 1 years varied significantly: 2025 ranks 1st highest AQI at 60 of Moderate air quality on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 18th Oct - 19th Oct 2025
Fontana, California, United States
6 AM18th Oct 2025
6 PM
5 AM19th Oct 2025
61AQI
18AQI
72AQI
21AQI
In the last 24 hours,
Fontana's AQI reached its highest point of 72 at 4 AM during the Night, while the lowest point, 18, was recorded at 3 PM during the Day between 18th Oct and 19th Oct 2025.
Day & Night AQI Trend : Sep - Oct 2025
Fontana, California, United States
--°C/°C
25°C20/33°C
24°C18/32°C
26°C18/36°C
28°C20/40°C
27°C20/36°C
23°C18/32°C
20°C18/25°C
21°C17/30°C
21°C16/30°C
22°C15/31°C
21°C17/29°C
21°C14/30°C
21°C14/31°C
19°C14/25°C
19°C12/29°C
20°C13/32°C
19°C12/31°C
20°C12/32°C
19°C12/30°C
20°C13/30°C
25°C17/35°C
23°C16/31°C
21°C12/33°C
16°C12/20°C
14°C12/16°C
15°C11/21°C
18°C10/28°C
22°C15/31°C
22°C13/32°C
21°C15/32°C
53AQI
45AQI
51AQI
47AQI
2025 Days Vs Air Quality
Fontana, California, United States
51%
106
49%
102
Total number of days with different AQI categories in last 293 days in 2025 (72 days remaining)
Under WHO’s Safe Air Quality Limits: 51%
Health Risk Level:
Considerable
In 2025, 51% of 293 days were within WHO’s safe air quality limits, and 49% exceeded them. The risk of health issues is Considerable, with potential for conditions in sensitive individuals.
Annual Air Quality Insights
Fontana, California, United States
AQI levels in 2025
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
51AQI
46AQI
34AQI
35AQI
40AQI
25AQI
26AQI
33AQI
28AQI
27AQI
31AQI
27AQI
38AQI
48AQI
52AQI
55AQI
54AQI
52AQI
60AQI
58AQI
57AQI
44AQI
32AQI
28AQI
35AQI
37AQI
47AQI
55AQI
49AQI
44AQI
42AQI
22AQI
21AQI
27AQI
43AQI
52AQI
52AQI
53AQI
52AQI
23AQI
27AQI
37AQI
35AQI
47AQI
48AQI
42AQI
39AQI
49AQI
30AQI
33AQI
47AQI
50AQI
44AQI
43AQI
47AQI
54AQI
53AQI
57AQI
59AQI
53AQI
49AQI
50AQI
53AQI
53AQI
52AQI
55AQI
56AQI
48AQI
39AQI
44AQI
51AQI
52AQI
51AQI
54AQI
55AQI
55AQI
56AQI
57AQI
56AQI
53AQI
56AQI
56AQI
62AQI
64AQI
61AQI
59AQI
54AQI
53AQI
53AQI
53AQI
56AQI
55AQI
56AQI
57AQI
52AQI
51AQI
47AQI
57AQI
63AQI
54AQI
49AQI
94AQI
60AQI
56AQI
56AQI
54AQI
50AQI
56AQI
55AQI
53AQI
51AQI
46AQI
48AQI
42AQI
44AQI
46AQI
48AQI
49AQI
45AQI
39AQI
39AQI
34AQI
33AQI
38AQI
40AQI
48AQI
51AQI
57AQI
57AQI
57AQI
61AQI
66AQI
66AQI
71AQI
61AQI
56AQI
56AQI
58AQI
60AQI
57AQI
59AQI
63AQI
58AQI
46AQI
46AQI
49AQI
51AQI
45AQI
53AQI
74AQI
53AQI
58AQI
57AQI
53AQI
47AQI
47AQI
43AQI
46AQI
48AQI
47AQI
46AQI
56AQI
52AQI
46AQI
52AQI
45AQI
35AQI
33AQI
32AQI
34AQI
34AQI
49AQI
56AQI
56AQI
55AQI
45AQI
38AQI
35AQI
38AQI
40AQI
42AQI
46AQI
47AQI
46AQI
39AQI
33AQI
38AQI
44AQI
47AQI
57AQI
47AQI
46AQI
51AQI
56AQI
61AQI
77AQI
72AQI
75AQI
63AQI
56AQI
49AQI
56AQI
38AQI
48AQI
43AQI
50AQI
46AQI
60AQI
39AQI
41AQI
47AQI
54AQI
50AQI
56AQI
44AQI
55AQI
No. of days
202549AQI
Highest AQI recorded in
August56AQI
Lowest AQI recorded in
March39AQI
Most & Least Polluted Years Over the Last 1 Years
Fontana's annual 2025 AQI (49) shows an average percentage change of NaN% (improved AQI) compared to previous years: .