Half Moon Bay, California, United States Historical Air Quality Analysis
Dive into detailed Air Quality Insights with historical data, monthly patterns, and yearly trends at your fingertips!
June Air Quality Analysis
Half Moon Bay, California, United States
AQI Trends: Highest and Lowest
Same Day Analysis (2nd June):
On this day, AQI across the 3 years varied significantly: 2026 ranks 2nd highest AQI at 31 of Good air quality, showing improvement over 2025 on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 1st Jun - 2nd Jun 2026
Half Moon Bay, California, United States
5 AM1st Jun 2026
8 PM
4 AM2nd Jun 2026
38AQI
28AQI
32AQI
29AQI
In the last 24 hours,
Half Moon Bay's AQI reached its highest point of 38 at 10 AM during the Day, while the lowest point, 28, was recorded at 6 AM during the Day between 1st Jun and 2nd Jun 2026.
Day & Night AQI Trend : May - Jun 2026
Half Moon Bay, California, United States
14°C11/16°C
13°C11/15°C
14°C12/19°C
12°C11/15°C
12°C10/14°C
12°C11/14°C
12°C11/14°C
13°C11/16°C
12°C10/14°C
14°C11/17°C
13°C10/20°C
15°C10/21°C
14°C10/18°C
15°C9/22°C
20°C15/27°C
17°C10/30°C
13°C10/17°C
12°C9/15°C
12°C9/15°C
13°C11/16°C
14°C12/19°C
13°C11/15°C
14°C11/17°C
13°C10/17°C
13°C12/18°C
12°C10/14°C
13°C10/17°C
13°C9/19°C
12°C9/16°C
12°C10/15°C
51AQI
29AQI
39AQI
30AQI
2026 Days Vs Air Quality
Half Moon Bay, California, United States
89%
134
11%
16
Total number of days with different AQI categories in last 153 days in 2026 (212 days remaining)
Under WHO’s Safe Air Quality Limits: 89%
Health Risk Level:
Low
In 2026, 89% of 153 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
Half Moon Bay, California, United States
AQI levels in 2026
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
24AQI (US)
18AQI (US)
18AQI (US)
24AQI (US)
21AQI (US)
20AQI (US)
24AQI (US)
20AQI (US)
23AQI (US)
39AQI (US)
43AQI (US)
47AQI (US)
52AQI (US)
55AQI (US)
61AQI (US)
48AQI (US)
53AQI (US)
60AQI (US)
49AQI (US)
47AQI (US)
51AQI (US)
49AQI (US)
52AQI (US)
49AQI (US)
46AQI (US)
47AQI (US)
43AQI (US)
50AQI (US)
55AQI (US)
52AQI (US)
42AQI (US)
46AQI (US)
50AQI (US)
49AQI (US)
49AQI (US)
47AQI (US)
43AQI (US)
36AQI (US)
47AQI (US)
47AQI (US)
48AQI (US)
46AQI (US)
47AQI (US)
53AQI (US)
53AQI (US)
44AQI (US)
45AQI (US)
53AQI (US)
43AQI (US)
44AQI (US)
42AQI (US)
35AQI (US)
35AQI (US)
40AQI (US)
45AQI (US)
42AQI (US)
35AQI (US)
32AQI (US)
35AQI (US)
39AQI (US)
52AQI (US)
45AQI (US)
45AQI (US)
39AQI (US)
37AQI (US)
37AQI (US)
36AQI (US)
37AQI (US)
34AQI (US)
38AQI (US)
39AQI (US)
37AQI (US)
33AQI (US)
34AQI (US)
36AQI (US)
34AQI (US)
33AQI (US)
33AQI (US)
37AQI (US)
33AQI (US)
34AQI (US)
38AQI (US)
38AQI (US)
33AQI (US)
34AQI (US)
33AQI (US)
34AQI (US)
29AQI (US)
27AQI (US)
27AQI (US)
34AQI (US)
34AQI (US)
27AQI (US)
30AQI (US)
27AQI (US)
30AQI (US)
29AQI (US)
37AQI (US)
29AQI (US)
34AQI (US)
36AQI (US)
31AQI (US)
35AQI (US)
37AQI (US)
33AQI (US)
33AQI (US)
34AQI (US)
33AQI (US)
30AQI (US)
28AQI (US)
28AQI (US)
30AQI (US)
31AQI (US)
33AQI (US)
29AQI (US)
26AQI (US)
26AQI (US)
27AQI (US)
28AQI (US)
24AQI (US)
21AQI (US)
30AQI (US)
35AQI (US)
34AQI (US)
30AQI (US)
30AQI (US)
34AQI (US)
36AQI (US)
34AQI (US)
31AQI (US)
29AQI (US)
45AQI (US)
50AQI (US)
57AQI (US)
57AQI (US)
56AQI (US)
49AQI (US)
41AQI (US)
48AQI (US)
49AQI (US)
46AQI (US)
43AQI (US)
28AQI (US)
28AQI (US)
28AQI (US)
26AQI (US)
28AQI (US)
29AQI (US)
31AQI (US)
31AQI (US)
41AQI (US)
44AQI (US)
36AQI (US)
31AQI (US)
37AQI (US)
31AQI (US)
No. of days
202638AQI (US)
Highest AQI (US) recorded in
February44AQI (US)
Lowest AQI (US) recorded in
June31AQI (US)
202534AQI (US)
Highest AQI (US) recorded in
December49AQI (US)
Lowest AQI (US) recorded in
July21AQI (US)
202433AQI (US)
Highest AQI (US) recorded in
December43AQI (US)
Lowest AQI (US) recorded in
March13AQI (US)
202336AQI (US)
Highest AQI (US) recorded in
November48AQI (US)
Lowest AQI (US) recorded in
December35AQI (US)
202231AQI (US)
Highest AQI (US) recorded in
August65AQI (US)
Lowest AQI (US) recorded in
September30AQI (US)
202165AQI (US)
Highest AQI (US) recorded in
August113AQI (US)
Lowest AQI (US) recorded in
May26AQI (US)
202064AQI (US)
Highest AQI (US) recorded in
October104AQI (US)
Lowest AQI (US) recorded in
November48AQI (US)
Most & Least Polluted Years Over the Last 7 Years
Half Moon Bay's annual 2026 AQI (US) (38) shows an average percentage change of -4.5% (improved AQI (US)) compared to previous years: 2020 (64), 2021 (65), 2022 (31), 2023 (36), 2024 (33), 2025 (34).