SmogRank / Cleaner or dirtier / Thailand

Thailand: cleaner or dirtier, 2026

In Thailand, 60 cities have enough days in both years to compare 2026 so far (1 January to 6 October) with the same days of 2025: 20 got dirtier and 38 cleaner.

The 20 cities that got dirtier, biggest rise first

#	City	2025	2026	Change
1	Bueng KanThailand	69	92	+11.9 µg/m³+63%
2	Mae SaiChiang Rai, Thailand	99	125	+10.1 µg/m³+29%
3	PhayaoThailand	86	105	+9.3 µg/m³+34%
4	Chiang RaiThailand	80	94	+7.8 µg/m³+32%
5	Suphan BuriThailand	66	79	+6.9 µg/m³+40%
6	Kamphaeng PhetThailand	70	82	+6.5 µg/m³+33%
7	PhraeThailand	86	95	+4.8 µg/m³+17%
8	UttaraditThailand	81	87	+2.9 µg/m³+11%
9	Si Sa KetThailand	64	69	+2.5 µg/m³+15%
10	Chiang MaiThailand	78	83	+2.3 µg/m³+10%
11	Mueang NonthaburiNonthaburi, Thailand	74	77	+1.6 µg/m³+7%
12	Sakon NakhonThailand	69	71	+1.3 µg/m³+7%
13	TrangThailand	52	54	+1.1 µg/m³+11%
14	PhichitThailand	76	78	+1.0 µg/m³+4%
15	RayongThailand	67	68	+0.9 µg/m³+5%
16	ChaiyaphumThailand	72	73	+0.7 µg/m³+3%
17	PattaniThailand	55	56	+0.6 µg/m³+5%
18	ChumphonThailand	57	58	+0.6 µg/m³+5%
19	KanchanaburiThailand	80	80	+0.1 µg/m³0%
20	PhetchabunThailand	75	75	+0.1 µg/m³0%

The 38 cities that got cleaner, biggest fall first

#	City	2025	2026	Change
1	YasothonThailand	93	69	−13.2 µg/m³−42%
2	KalasinThailand	89	80	−4.5 µg/m³−15%
3	Bang NaBangkok, Thailand	91	84	−3.9 µg/m³−13%
4	Nong KhaemBangkok, Thailand	86	79	−3.8 µg/m³−14%
5	Lop BuriLopburi, Thailand	82	75	−3.5 µg/m³−14%
6	Bang KapiBangkok, Thailand	81	75	−3.4 µg/m³−13%
7	Sing BuriThailand	85	79	−3.4 µg/m³−12%
8	TratThailand	75	69	−3.2 µg/m³−14%
9	Hua HinPrachuap Khiri Khan, Thailand	65	60	−3.0 µg/m³−18%
10	Amnat CharoenThailand	82	77	−2.8 µg/m³−11%
11	BangkokThailand	80	74	−2.8 µg/m³−11%
12	Phra Nakhon Si AyutthayaThailand	75	70	−2.7 µg/m³−12%
13	Nong ChokBangkok, Thailand	77	73	−2.4 µg/m³−10%
14	Ban Samae DamBangkok, Thailand	81	77	−2.4 µg/m³−9%
15	Buri RamBuriram, Thailand	69	65	−2.1 µg/m³−11%
16	Nong Bua LamphuThailand	77	73	−2.1 µg/m³−9%
17	Nakhon PathomThailand	74	70	−2.1 µg/m³−10%
18	Ubon RatchathaniThailand	87	83	−2.1 µg/m³−7%
19	MukdahanThailand	82	78	−1.9 µg/m³−7%
20	SukhothaiThailand	80	76	−1.7 µg/m³−7%
21	Saphan SungBangkok, Thailand	82	79	−1.7 µg/m³−7%
22	Khlong Sam WaBangkok, Thailand	87	84	−1.7 µg/m³−6%
23	Roi EtThailand	79	76	−1.5 µg/m³−6%
24	Bueng KumBangkok, Thailand	80	78	−1.4 µg/m³−6%
25	SurinThailand	70	68	−1.4 µg/m³−7%
26	Ban Khlong PrawetBangkok, Thailand	74	72	−1.3 µg/m³−6%
27	Nakhon RatchasimaThailand	79	76	−1.3 µg/m³−5%
28	Ban Thai TanAng Thong, Thailand	76	74	−1.0 µg/m³−4%
29	Maha SarakhamThailand	77	75	−1.0 µg/m³−4%
30	Lak SiBangkok, Thailand	79	77	−1.0 µg/m³−4%
31	Khan Na YaoBangkok, Thailand	85	83	−0.9 µg/m³−3%
32	Sai MaiBangkok, Thailand	76	75	−0.8 µg/m³−4%
33	Phra PradaengSamut Prakan, Thailand	76	74	−0.7 µg/m³−3%
34	Nakhon NayokThailand	65	64	−0.4 µg/m³−2%
35	AranyaprathetSa Kaeo, Thailand	71	70	−0.4 µg/m³−2%
36	PhatthalungThailand	56	55	−0.4 µg/m³−3%
37	Samut SakhonThailand	77	76	−0.4 µg/m³−2%
38	Bang PakongChachoengsao, Thailand	62	62	−0.1 µg/m³−1%

Means in US AQI over the days a city was measured in both years, the same calendar days each year; a city needs 55% of the days paired, and at least 30. The change is in µg/m³ and per cent. How we compare.

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Updated 2026-10-07 12:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.