Tsukawaki, Oita, Japan Historical Air Quality Analysis

Dive into detailed Air Quality Insights with historical data, monthly patterns, and yearly trends at your fingertips!

Good

050

Moderate

100

Poor

150

Unhealthy

200

Severe

300

Hazardous

301+

September Air Quality Analysis
Tsukawaki, Oita, Japan

2021

2022

2023

2024

2025

AQI

Days

Days	2025	2024	2023	2022	2021
Sep. 1	39	31	31		45
Sep. 2	42	51	35	35	21
Sep. 3	38	56	31	36	42
Sep. 4	25	48	36	29	32
Sep. 5	23	75	33	19	35
Sep. 6	30	74	35	30	43
Sep. 7	36	69	42	40	48
Sep. 8	29	75	48	42	50
Sep. 9	30	59	42		42
Sep. 10	28	27	46	41	52
Sep. 11	32	33	40	34	49
Sep. 12	30	31	36	33	45
Sep. 13	31	34	35	33	52
Sep. 14	30	32	40	39	35
Sep. 15	30	28	48	41	27
Sep. 16	35	39	45	36	30
Sep. 17	30	37	47	43	26
Sep. 18	26	29	40	32	33
Sep. 19	27	32	36	28	32
Sep. 20	33	26	41	38	45
Sep. 21		36	39	33	40
Sep. 22		25	31	48	51
Sep. 23		30	25	63	62
Sep. 24		40	34	48	41
Sep. 25		45	36	47	46
Sep. 26		45	25	65	55
Sep. 27		51	43	39	45
Sep. 28		47	41	49	36
Sep. 29		39	41	40	29
Sep. 30		40	57	36	37

AQI Trends: Highest and Lowest

Highest AQI recorded on

5th Sep 2024

75AQI

Lowest AQI recorded on

5th Sep 2022

19AQI

Same Day Analysis (20th September ):
On this day, AQI across the 5 years varied significantly: 2025 ranks 4th highest AQI at 33 of Good air quality, showing improvement over 2023, 2022 and 2021 on the same day.

Day & Night AQI Trend: 20th Sep - 21st Sep 2025
Tsukawaki, Oita, Japan

AQI

Day

Night

5 AM20th Sep 2025

6 PM

4 AM21st Sep 2025

Day time

Avg. Highest Time

1PM20th Sep

64AQI

Avg. Lowest Time

6PM20th Sep

20AQI

Night time

Avg. Highest Time

4AM21st Sep

31AQI

Avg. Lowest Time

7PM20th Sep

20AQI

In the last 24 hours,

Tsukawaki's AQI reached its highest point of 64 at 1 PM during the Day, while the lowest point, 20, was recorded at 7 PM during the Night between 20th Sep and 21st Sep 2025.

Day & Night AQI Trend : Aug - Sep 2025
Tsukawaki, Oita, Japan

AugSep

22nd - 23rd23rd - 24th24th - 25th25th - 26th26th - 27th27th - 28th28th - 29th29th - 30th30th - 31st31st - 01st01st - 02nd02nd - 03rd03rd - 04th04th - 05th05th - 06th06th - 07th07th - 08th08th - 09th09th - 10th10th - 11th11th - 12th12th - 13th13th - 14th14th - 15th15th - 16th16th - 17th17th - 18th18th - 19th19th - 20th20th - 21st21st

Day

Night

26°C22/31°C

26°C23/31°C

27°C23/33°C

26°C23/30°C

27°C23/32°C

26°C23/30°C

27°C23/32°C

27°C23/34°C

27°C23/33°C

26°C23/31°C

27°C23/32°C

26°C23/31°C

27°C23/33°C

25°C23/28°C

26°C23/30°C

27°C23/33°C

27°C23/32°C

24°C22/27°C

25°C22/30°C

26°C21/32°C

25°C23/29°C

26°C24/30°C

26°C23/32°C

26°C23/30°C

24°C22/28°C

24°C20/29°C

24°C22/26°C

5 AM

11 AM

6 PM

11 PM

4 AM

--°C/°C

Day time

Avg. Highest Time

5 AM - 8 AM

36AQI

4 hours / Day

120 hours / Month

Avg. Lowest Time

9 AM

31AQI

1 hours / Day

30 hours / Month

In the last 30 days, during the daytime, the highest AQI was between 5 AM to 8 AM (Avg. 36), while the lowest AQI was between 9 AM to 9 AM (Avg. 31).

Night time

Avg. Highest Time

2 AM - 4 AM

37AQI

3 hours / Day

90 hours / Month

Avg. Lowest Time

12 AM - 1 AM

35AQI

2 hours / Day

60 hours / Month

In the last 30 days, during the daytime, the highest AQI was between 2 AM to 4 AM (Avg. 37), while the lowest AQI was between 12 AM to 1 AM (Avg. 35).

2025 Days Vs Air Quality
Tsukawaki, Oita, Japan

2025

74%

195

26%

Total number of days with different AQI categories in last 264 days in 2025 (101 days remaining)

Good

195 Days

Moderate

68 Days

Poor

0 Days

Unhealthy

0 Days

Severe

0 Days

Hazardous

0 Days

Under WHO’s Safe Air Quality Limits: 74%

Health Risk Level:

Low

In 2025, 74% of 264 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
Tsukawaki, Oita, Japan

AQI levels in 2025

AQI

PM2.5

PM10

SO2

NO2

Sun.Mon.Tue.Wed.Thu.Fri.Sat.

Jan.

Feb.

Mar.

Apr.

May

Jun.

Jul.

Aug.

Sep.

Oct.

Nov.

Dec.

50AQI

44AQI

50AQI

46AQI

44AQI

42AQI

49AQI

43AQI

31AQI

No. of days

Jan.Feb.Mar.Apr.MayJun.Jul.Aug.Sep.Oct.Nov.Dec.Total Days

202545AQI

195

Highest AQI recorded in

January

50AQI

Lowest AQI recorded in

September

31AQI

202443AQI

282

Highest AQI recorded in

April

53AQI

Lowest AQI recorded in

July

37AQI

202344AQI

261

101

Highest AQI recorded in

April

53AQI

Lowest AQI recorded in

August

32AQI

202248AQI

206

112

Highest AQI recorded in

May

57AQI

Lowest AQI recorded in

September

39AQI

202146AQI

232

122

Highest AQI recorded in

February

54AQI

Lowest AQI recorded in

August

32AQI

202049AQI

146

104

Highest AQI recorded in

March

68AQI

Lowest AQI recorded in

July

32AQI

Most & Least Polluted Years Over the Last 6 Years

Most Polluted Year Recorded

2020(Avg.)

49AQI

Least Polluted Year Recorded

2024(Avg.)

43AQI

Tsukawaki's annual 2025 AQI (45) shows an average percentage change of -2.05% (improved AQI) compared to previous years: 2020 (49), 2021 (46), 2022 (48), 2023 (44), 2024 (43).


5 AM	27
6 AM	27
7 AM	26
8 AM	27
9 AM	49
10 AM	59
11 AM	60
12 PM	62
1 PM	64
2 PM	52
3 PM	30
4 PM	24
5 PM	21
6 PM	20
7 PM	20
8 PM	22
9 PM	24
10 PM	24
11 PM	26
12 AM	24
1 AM	25
2 AM	28
3 AM	28
4 AM	31

Tsukawaki, Oita, Japan Historical Air Quality Analysis

September Air Quality AnalysisTsukawaki, Oita, Japan

Day & Night AQI Trend: 20th Sep - 21st Sep 2025Tsukawaki, Oita, Japan

Day & Night AQI Trend : Aug - Sep 2025Tsukawaki, Oita, Japan

2025 Days Vs Air Quality Tsukawaki, Oita, Japan

Annual Air Quality InsightsTsukawaki, Oita, Japan

AQI levels in 2025

No. of days

September Air Quality Analysis
Tsukawaki, Oita, Japan

Day & Night AQI Trend: 20th Sep - 21st Sep 2025
Tsukawaki, Oita, Japan

Day & Night AQI Trend : Aug - Sep 2025
Tsukawaki, Oita, Japan

2025 Days Vs Air Quality
Tsukawaki, Oita, Japan

Annual Air Quality Insights
Tsukawaki, Oita, Japan