Omachi, Nagano, Japan 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
Omachi, Nagano, Japan
AQI Trends: Highest and Lowest
Same Day Analysis (1st August ):
On this day, AQI across the 5 years varied significantly: 2025 ranks 1st highest AQI at 46 of Good air quality on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 2nd Aug - 3rd Aug 2025
Omachi, Nagano, Japan
4 AM2nd Aug 2025
7 PM
3 AM3rd Aug 2025
AQI
AQI
56AQI
42AQI
In the last 24 hours,
Omachi's AQI reached its highest point of 56 at 12 PM during the Night, while the lowest point, undefined, was recorded at 3 AM during the Night between 2nd Aug and 3rd Aug 2025.
Day & Night AQI Trend : Jul - Aug 2025
Omachi, Nagano, Japan
20°C14/28°C
19°C13/29°C
21°C14/30°C
21°C15/28°C
22°C16/29°C
21°C16/27°C
20°C14/27°C
19°C13/26°C
20°C13/27°C
22°C16/29°C
22°C18/28°C
21°C15/25°C
20°C12/28°C
19°C16/21°C
22°C16/29°C
21°C14/29°C
22°C15/30°C
22°C15/30°C
21°C15/28°C
21°C15/29°C
22°C15/30°C
22°C15/30°C
23°C17/30°C
22°C16/28°C
21°C15/30°C
22°C15/30°C
22°C15/31°C
22°C15/31°C
22°C15/31°C
--°C/°C
--°C/°C
47AQI
36AQI
46AQI
46AQI
2025 Days Vs Air Quality
Omachi, Nagano, Japan
85%
182
15%
31
Total number of days with different AQI categories in last 214 days in 2025 (151 days remaining)
Under WHO’s Safe Air Quality Limits: 85%
Health Risk Level:
Low
In 2025, 85% of 214 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
Omachi, Nagano, Japan
AQI levels in 2025
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
32AQI
32AQI
29AQI
29AQI
28AQI
35AQI
29AQI
28AQI
27AQI
25AQI
27AQI
28AQI
28AQI
31AQI
28AQI
26AQI
27AQI
28AQI
32AQI
33AQI
37AQI
36AQI
49AQI
43AQI
38AQI
35AQI
31AQI
31AQI
31AQI
33AQI
32AQI
40AQI
38AQI
37AQI
33AQI
34AQI
31AQI
33AQI
31AQI
30AQI
30AQI
32AQI
30AQI
31AQI
34AQI
31AQI
37AQI
38AQI
33AQI
33AQI
31AQI
31AQI
32AQI
32AQI
32AQI
34AQI
38AQI
47AQI
43AQI
47AQI
43AQI
39AQI
38AQI
35AQI
33AQI
36AQI
37AQI
36AQI
39AQI
37AQI
33AQI
46AQI
38AQI
38AQI
26AQI
26AQI
27AQI
23AQI
31AQI
44AQI
48AQI
60AQI
60AQI
74AQI
78AQI
68AQI
46AQI
41AQI
36AQI
35AQI
33AQI
28AQI
24AQI
25AQI
32AQI
29AQI
36AQI
41AQI
30AQI
43AQI
40AQI
47AQI
27AQI
35AQI
23AQI
31AQI
43AQI
50AQI
63AQI
51AQI
45AQI
49AQI
32AQI
31AQI
41AQI
50AQI
47AQI
47AQI
43AQI
54AQI
50AQI
36AQI
38AQI
34AQI
40AQI
36AQI
33AQI
36AQI
33AQI
27AQI
28AQI
34AQI
42AQI
49AQI
51AQI
52AQI
39AQI
42AQI
43AQI
57AQI
63AQI
54AQI
54AQI
46AQI
32AQI
33AQI
36AQI
33AQI
39AQI
31AQI
28AQI
27AQI
38AQI
31AQI
35AQI
35AQI
45AQI
48AQI
56AQI
58AQI
54AQI
39AQI
43AQI
48AQI
39AQI
29AQI
33AQI
42AQI
46AQI
49AQI
53AQI
54AQI
56AQI
46AQI
46AQI
43AQI
43AQI
49AQI
46AQI
49AQI
54AQI
56AQI
52AQI
54AQI
57AQI
60AQI
55AQI
59AQI
62AQI
63AQI
58AQI
49AQI
48AQI
49AQI
45AQI
39AQI
45AQI
37AQI
39AQI
38AQI
39AQI
39AQI
43AQI
45AQI
47AQI
48AQI
44AQI
42AQI
46AQI
50AQI
48AQI
47AQI
46AQI
32AQI
34AQI
42AQI
39AQI
40AQI
44AQI
48AQI
46AQI
No. of days
202540AQI
Highest AQI recorded in
July48AQI
Lowest AQI recorded in
January32AQI
202435AQI
Highest AQI recorded in
March44AQI
Lowest AQI recorded in
December27AQI
202341AQI
Highest AQI recorded in
July49AQI
Lowest AQI recorded in
September31AQI
202239AQI
Highest AQI recorded in
May50AQI
Lowest AQI recorded in
August17AQI
202133AQI
Highest AQI recorded in
June54AQI
Lowest AQI recorded in
January16AQI
202021AQI
Highest AQI recorded in
August49AQI
Lowest AQI recorded in
May7AQI
Most & Least Polluted Years Over the Last 6 Years
Omachi's annual 2025 AQI (40) shows an average percentage change of 26.5% (worsened AQI) compared to previous years: 2020 (21), 2021 (33), 2022 (39), 2023 (41), 2024 (35).