Eureka, California, United States Historical Air Quality Analysis
Dive into detailed Air Quality Insights with historical data, monthly patterns, and yearly trends at your fingertips!
August Air Quality Analysis
Eureka, California, United States
AQI Trends: Highest and Lowest
Same Day Analysis (13th August ):
On this day, AQI across the 3 years varied significantly: 2025 ranks 2nd highest AQI at 26 of Good air quality, showing improvement over 2021 on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 14th Aug - 15th Aug 2025
Eureka, California, United States
6 AM14th Aug 2025
8 PM
5 AM15th Aug 2025
26AQI
15AQI
29AQI
26AQI
In the last 24 hours,
Eureka's AQI reached its highest point of 29 at 11 PM during the Night, while the lowest point, undefined, was recorded at 5 AM during the Night between 14th Aug and 15th Aug 2025.
Day & Night AQI Trend : Jul - Aug 2025
Eureka, California, United States
14°C12/16°C
13°C13/14°C
13°C11/17°C
13°C11/17°C
13°C12/16°C
14°C13/15°C
14°C12/15°C
14°C13/16°C
14°C13/15°C
14°C13/15°C
14°C13/16°C
14°C12/16°C
14°C11/16°C
14°C12/15°C
14°C13/16°C
14°C13/16°C
14°C13/16°C
14°C13/16°C
14°C13/15°C
14°C13/16°C
14°C12/17°C
16°C13/18°C
16°C15/17°C
17°C13/22°C
18°C14/23°C
17°C15/19°C
16°C13/19°C
15°C13/18°C
14°C13/16°C
14°C13/16°C
--°C/°C
28AQI
25AQI
28AQI
25AQI
2025 Days Vs Air Quality
Eureka, California, United States
96%
216
4%
9
Total number of days with different AQI categories in last 227 days in 2025 (138 days remaining)
Under WHO’s Safe Air Quality Limits: 96%
Health Risk Level:
Very Low
In 2025, 96% of 227 days were within WHO’s safe air quality limits. The risk of health issues is Very Low, but health impacts are still unclear.
Annual Air Quality Insights
Eureka, California, United States
AQI levels in 2025
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
36AQI
33AQI
34AQI
24AQI
31AQI
28AQI
23AQI
33AQI
37AQI
46AQI
28AQI
27AQI
28AQI
44AQI
52AQI
50AQI
43AQI
43AQI
52AQI
41AQI
52AQI
56AQI
51AQI
53AQI
38AQI
38AQI
43AQI
54AQI
64AQI
66AQI
49AQI
34AQI
31AQI
31AQI
30AQI
31AQI
41AQI
31AQI
36AQI
33AQI
27AQI
41AQI
49AQI
34AQI
28AQI
34AQI
33AQI
35AQI
39AQI
29AQI
28AQI
36AQI
50AQI
34AQI
31AQI
30AQI
38AQI
44AQI
45AQI
40AQI
27AQI
29AQI
29AQI
34AQI
22AQI
30AQI
38AQI
27AQI
35AQI
38AQI
27AQI
25AQI
25AQI
26AQI
30AQI
23AQI
26AQI
30AQI
21AQI
23AQI
23AQI
30AQI
31AQI
36AQI
32AQI
23AQI
27AQI
24AQI
30AQI
24AQI
22AQI
22AQI
25AQI
24AQI
27AQI
25AQI
17AQI
20AQI
27AQI
23AQI
27AQI
26AQI
29AQI
31AQI
37AQI
37AQI
32AQI
33AQI
37AQI
39AQI
33AQI
38AQI
43AQI
43AQI
26AQI
31AQI
24AQI
23AQI
27AQI
32AQI
30AQI
32AQI
24AQI
27AQI
28AQI
30AQI
33AQI
30AQI
31AQI
23AQI
21AQI
19AQI
20AQI
23AQI
24AQI
25AQI
26AQI
24AQI
23AQI
20AQI
30AQI
27AQI
22AQI
29AQI
27AQI
20AQI
27AQI
33AQI
25AQI
33AQI
35AQI
42AQI
48AQI
47AQI
36AQI
38AQI
35AQI
27AQI
26AQI
27AQI
31AQI
37AQI
42AQI
43AQI
39AQI
36AQI
28AQI
20AQI
22AQI
31AQI
34AQI
20AQI
18AQI
20AQI
23AQI
27AQI
23AQI
26AQI
27AQI
33AQI
34AQI
31AQI
30AQI
23AQI
28AQI
39AQI
33AQI
30AQI
26AQI
24AQI
32AQI
48AQI
40AQI
34AQI
35AQI
39AQI
31AQI
29AQI
27AQI
32AQI
28AQI
32AQI
24AQI
23AQI
20AQI
21AQI
19AQI
21AQI
27AQI
28AQI
29AQI
26AQI
23AQI
23AQI
30AQI
30AQI
29AQI
26AQI
25AQI
32AQI
37AQI
33AQI
27AQI
27AQI
26AQI
42AQI
35AQI
29AQI
29AQI
26AQI
31AQI
29AQI
28AQI
No. of days
202531AQI
Highest AQI recorded in
January42AQI
Lowest AQI recorded in
May26AQI
202434AQI
Highest AQI recorded in
April55AQI
Lowest AQI recorded in
May22AQI
202344AQI
Highest AQI recorded in
November47AQI
Lowest AQI recorded in
December44AQI
202137AQI
Highest AQI recorded in
August43AQI
Lowest AQI recorded in
July13AQI
202078AQI
Highest AQI recorded in
October78AQI
Lowest AQI recorded in
October78AQI
Most & Least Polluted Years Over the Last 5 Years
Eureka's annual 2025 AQI (31) shows an average percentage change of -27.4% (improved AQI) compared to previous years: 2020 (78), 2021 (37), 2023 (44), 2024 (34).