Indicator · TLI ind_pm25_days_exceeding_who

Annual Count of Days Exceeding WHO Daily PM2.5 Guideline

จำนวนวันต่อปีที่ค่า PM2.5 เกินเกณฑ์มาตรฐานรายวันขององค์การอนามัยโลก

AS OF 25 OCT 2026days/yr > WHOWeight 0.5

Source

OpenAQ (Pollution Control Department feed)

Crowd-sourced air-quality aggregator that ingests Thai PCD government sensor feeds and exposes a uniform API. Refresh: daily upstream; TLI re-pulls daily during burning season and weekly otherwise.

Goalposts

The 0-to-100 score for this indicator is normalized against fixed methodology goalposts. The values below define the band; click through to the methodology page for the framework that anchors them.

Score 100: 30days/yr > WHO
Score 0: 300days/yr > WHO
Direction: Lower is better
Anchor: Hybrid: international anchor and Thai distribution · WHO 2021 daily threshold (15 µg/m³ 24-hour)

The threshold for an exceedance day is the WHO 2021 24-hour guideline of 15 µg/m³. The score-100 floor at 30 days and the score-zero ceiling at 300 days are fitted to the observed Thai distribution. The 300-day ceiling was re-fit on 2026-04-30 from 200, where Bangkok (296 days) and Chiang Rai (200 days) clipped together with no within-bad-tier discrimination. The 30-day floor preserves a meaningful gap above zero.

Live distribution: 1 of 77 clip at the score-0 floor.

Which Thai province leads on Annual Count of Days Exceeding WHO Daily PM2.5 Guideline?

Trang leads Thailand on Annual Count of Days Exceeding WHO Daily PM2.5 Guideline with a raw value of 68.4 days/yr > WHO, earning a TLI score of 85.8/100. The bottom of the distribution is Prachin Buri (305 days/yr > WHO, score 0/100).

Coverage

77 of 77 Thai provinces. Median score: 40.4. Each province's score is normalized 0–100 against fixed goalposts; a higher score is more favorable.

Reading the columns.Raw valuethe actual measurement in days/yr > WHO.Scorenormalized 0–100 against fixed methodology goalposts (not a percentile). Lower is better.

Top scorers

Rank	Province	Raw value (days/yr > WHO)	Score
1	Trang	68.4	85.8
2	Phatthalung	68.7	85.7
3	Narathiwat	90.6	77.6
4	Nakhon Si Thammarat	100.6	73.8
5	Si Sa Ket	106.3	71.7

Lowest scorers

Rank	Province	Raw value (days/yr > WHO)	Score
77	Prachin Buri	305	0
76	Phitsanulok	296.5	1.3
75	Saraburi	294.7	2
74	Kalasin	292.7	2.7
73	Phra Nakhon Si Ayutthaya	285.3	5.5

Show all 77 provinces rankedSorted highest to lowest score

Rank	Province	Raw value (days/yr > WHO)	Score
1	Trang	68.4	85.8
2	Phatthalung	68.7	85.7
3	Narathiwat	90.6	77.6
4	Nakhon Si Thammarat	100.6	73.8
5	Si Sa Ket	106.3	71.7
6	Pattani	113.1	69.2
7	Yala	113.9	68.9
8	Chumphon	125.3	64.7
9	Phrae	135.1	61.1
10	Phangnga	138.2	59.9
11	Phuket	142.9	58.2
12	Chaiyaphum	144.6	57.5
13	Krabi	144.9	57.4
14	Satun	149.7	55.7
15	Chanthaburi	157.5	52.8
16	Chiang Rai	157.9	52.6
17	Buri Ram	162.2	51
18	Prachuap Khiri Khan	162.3	51
19	Trat	164.2	50.3
20	Chachoengsao	166.8	49.3
21	Nakhon Pathom	167.7	49
22	Sakon Nakhon	168.4	48.7
23	Yasothon	169.7	48.3
24	Samut Songkhram	171.1	47.7
25	Surin	172.3	47.3
26	Sa Kaeo	175.8	46
27	Kamphaeng Phet	177.8	45.2
28	Ubon Ratchathani	181.8	43.8
29	Nong Bua Lam Phu	182.1	43.7
30	Phichit	183.2	43.3
31	Phetchabun	184.5	42.8
32	Udon Thani	185.9	42.3
33	Amnat Charoen	186.4	42.1
34	Ranong	187.2	41.8
35	Nakhon Sawan	189.2	41
36	Uttaradit	189.4	41
37	Ang Thong	189.5	40.9
38	Khon Kaen	190.2	40.7
39	Lampang	190.9	40.4
40	Nakhon Ratchasima	191.3	40.3
41	Bueng Kan	192.2	39.9
42	Roi Et	194.7	39
43	Songkhla	194.9	38.9
44	Sing Buri	200.7	36.8
45	Nan	200.8	36.8
46	Nakhon Phanom	202.7	36
47	Nong Khai	205.7	34.9
48	Nonthaburi	205.8	34.9
49	Loei	206.4	34.7
50	Maha Sarakham	210.4	33.2
51	Rayong	211.4	32.8
52	Kanchanaburi	212.1	32.6
53	Lamphun	213.1	32.2
54	Mae Hong Son	213.2	32.1
55	Samut Sakhon	214.9	31.5
56	Pathum Thani	216	31.1
57	Tak	218.4	30.2
58	Ratchaburi	219.7	29.7
59	Chiang Mai	220.7	29.4
60	Chon Buri	228.3	26.6
61	Bangkok	228.4	26.5
62	Samut Prakan	229.6	26.1
63	Mukdahan	239.4	22.4
64	Chai Nat	243.1	21.1
65	Suphan Buri	249.4	18.7
66	Phetchaburi	253.3	17.3
67	Lopburi	258.7	15.3
68	Surat Thani	261.5	14.3
69	Nakhon Nayok	262.6	13.8
70	Uthai Thani	264.3	13.2
71	Sukhothai	269.8	11.2
72	Phayao	284.9	5.6
73	Phra Nakhon Si Ayutthaya	285.3	5.5
74	Kalasin	292.7	2.7
75	Saraburi	294.7	2
76	Phitsanulok	296.5	1.3
77	Prachin Buri	305	0

Methodology

See the methodology page for the full TLI scoring approach, including how this indicator's category Environment & Climate combines with the other six categories via geometric mean.

Cite as: "Annual Count of Days Exceeding WHO Daily PM2.5 Guideline." Thailand Livability Index, 2026. CC BY-NC 4.0.

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