Yokomachi, Itoigawa, Niigata, Japan Historical Air Quality Analysis
Dive into detailed Air Quality Insights with historical data, monthly patterns, and yearly trends at your fingertips!
February Air Quality Analysis
Yokomachi, Itoigawa, Niigata, Japan
AQI Trends: Highest and Lowest
Same Day Analysis (9th February):
On this day, AQI across the 5 years varied significantly: 2026 ranks 2nd highest AQI at 33 of Good air quality, showing improvement over 2023 on the same day.
Download 2024 Annual Data
World Air Quality Report

Day & Night AQI Trend: 8th Feb - 9th Feb 2026
Yokomachi, Itoigawa, Niigata, Japan
6 AM8th Feb 2026
5 PM
5 AM9th Feb 2026
29AQI
8AQI
54AQI
8AQI
In the last 24 hours,
Yokomachi's AQI reached its highest point of 54 at 4 AM during the Night, while the lowest point, 8, was recorded at 3 AM during the Night between 8th Feb and 9th Feb 2026.
Day & Night AQI Trend : Jan - Feb 2026
Yokomachi, Itoigawa, Niigata, Japan
3°C0/5°C
1°C0/3°C
4°C0/8°C
2°C1/4°C
4°C0/7°C
5°C3/8°C
4°C1/10°C
2°C-2/3°C
4°C-1/9°C
1°C-3/4°C
-2°C-4/0°C
-1°C-2/0°C
0°C-6/2°C
1°C0/2°C
-1°C-1/0°C
0°C-3/2°C
2°C-3/6°C
1°C-2/2°C
0°C-1/1°C
0°C0/1°C
0°C-3/2°C
0°C-3/3°C
1°C-2/3°C
0°C-4/3°C
2°C-3/8°C
5°C1/10°C
3°C0/5°C
-1°C-4/0°C
-3°C-5/-1°C
-1°C-5/3°C
46AQI
28AQI
44AQI
27AQI
2026 Days Vs Air Quality
Yokomachi, Itoigawa, Niigata, Japan
100%
40
Total number of days with different AQI categories in last 41 days in 2026 (324 days remaining)
Under WHO’s Safe Air Quality Limits: 100%
Health Risk Level:
Very Low
In 2026, 100% of 41 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
Yokomachi, Itoigawa, Niigata, Japan
AQI levels in 2026
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
22AQI (US)
31AQI (US)
34AQI (US)
31AQI (US)
34AQI (US)
25AQI (US)
23AQI (US)
26AQI (US)
28AQI (US)
29AQI (US)
27AQI (US)
28AQI (US)
31AQI (US)
27AQI (US)
46AQI (US)
50AQI (US)
45AQI (US)
34AQI (US)
49AQI (US)
32AQI (US)
19AQI (US)
25AQI (US)
34AQI (US)
35AQI (US)
42AQI (US)
27AQI (US)
36AQI (US)
33AQI (US)
27AQI (US)
39AQI (US)
44AQI (US)
34AQI (US)
42AQI (US)
33AQI (US)
38AQI (US)
41AQI (US)
37AQI (US)
20AQI (US)
10AQI (US)
33AQI (US)
33AQI (US)
32AQI (US)
No. of days
202633AQI (US)
Highest AQI (US) recorded in
January33AQI (US)
Lowest AQI (US) recorded in
February32AQI (US)
202541AQI (US)
Highest AQI (US) recorded in
October50AQI (US)
Lowest AQI (US) recorded in
September29AQI (US)
202437AQI (US)
Highest AQI (US) recorded in
April51AQI (US)
Lowest AQI (US) recorded in
December27AQI (US)
202338AQI (US)
Highest AQI (US) recorded in
April48AQI (US)
Lowest AQI (US) recorded in
January30AQI (US)
202237AQI (US)
Highest AQI (US) recorded in
May47AQI (US)
Lowest AQI (US) recorded in
December27AQI (US)
202134AQI (US)
Highest AQI (US) recorded in
June49AQI (US)
Lowest AQI (US) recorded in
January24AQI (US)
202030AQI (US)
Highest AQI (US) recorded in
August55AQI (US)
Lowest AQI (US) recorded in
December19AQI (US)
Most & Least Polluted Years Over the Last 7 Years
Yokomachi's annual 2026 AQI (US) (33) shows an average percentage change of -9.3% (improved AQI (US)) compared to previous years: 2020 (30), 2021 (34), 2022 (37), 2023 (38), 2024 (37), 2025 (41).