SmogRank / South Africa / Gauteng / Thembisa

Thembisa, month by month

Thembisa has a measured daily mean on 185 days since 1 January 2023. Its worst month was September 2026, at 94 US AQI (32.2 µg/m³), 109th of 2,981 cities on that month's world ranking. Its cleanest was February 2024, at 60 US AQI (13.8 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 200)54 days measured
JannoneFebnoneMarnoneAprnoneMaynoneJunnoneJulnoneAug17 daysSep94#109Oct57#363
2025too few days for a mean (a year needs 256)0 days measured
JannoneFebnoneMarnoneAprnoneMaynoneJunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
2024too few days for a mean (a year needs 257)52 days measured
Jan63#418Feb60#380Mar7 daysAprnoneMaynoneJunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
2023too few days for a mean (a year needs 256)79 days measured
Jan61#269Feb2 daysMar11 daysApr13 daysMay16 daysJun9 daysJul1 dayAug2 daysSep3 daysOctnoneNovnoneDecnone
Each square is a month's mean PM2.5 in US AQI from Thembisa's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Thembisa marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

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

Months without a mean, and why

41 months
MonthWhy
Aug 202617 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks.
Jul 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jun 2026No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
May 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Apr 2026No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Feb 2026No day measured. The others: 28 with under 18 hours of readings or readings that failed our checks.
Jan 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Dec 2025No day measured.
Nov 2025No day measured.
Oct 2025No day measured.
Sep 2025No day measured.
Aug 2025No day measured.
Jul 2025No day measured.
Jun 2025No day measured.
May 2025No day measured.
Apr 2025No day measured.
Mar 2025No day measured.
Feb 2025No day measured.
Jan 2025No day measured.
Dec 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Sep 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Aug 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jul 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jun 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
May 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Apr 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 20247 of 31 days measured; a month needs 22. The others: 24 with under 18 hours of readings or readings that failed our checks.
Dec 2023No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2023No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 2023No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Sep 20233 of 30 days measured; a month needs 21. The others: 27 with under 18 hours of readings or readings that failed our checks.
Aug 20232 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks.
Jul 20231 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 29 with under 18 hours of readings or readings that failed our checks.
Jun 20239 of 30 days measured; a month needs 21. The others: 21 with under 18 hours of readings or readings that failed our checks.
May 202316 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks.
Apr 202313 of 30 days measured; a month needs 21. The others: 3 missing from OpenAQ's archive, 14 with under 18 hours of readings or readings that failed our checks.
Mar 202311 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive.
Feb 20232 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive, 1 with under 18 hours of readings or readings that failed our checks.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Thembisa's worst months

MonthUS AQIDays measuredWorld rankEpisode
September 2026 9432.2 µg/m³26 of 30109thof 2,981North-eastern South Africa and Zimbabwe, September 2026
January 2024 6315.8 µg/m³24 of 31418thof 2,385–
January 2023 6114.2 µg/m³22 of 31269thof 1,261–
February 2024 6013.8 µg/m³21 of 29380thof 2,486–

Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.

Thembisa's worst days

DayUS AQIEpisode
8 Jul 2023 190111.0 µg/m³–
12 Sept 2026 184103.0 µg/m³–
18 Jun 2023 17792.9 µg/m³–
19 Jun 2023 17792.8 µg/m³–
11 Sept 2026 16981.0 µg/m³–
4 Jun 2023 16778.2 µg/m³–
13 Sept 2026 16270.7 µg/m³–
16 Sept 2026 15966.3 µg/m³North-eastern South Africa and Zimbabwe, September 2026
10 Sept 2026 15865.4 µg/m³–
3 Jun 2023 15865.3 µg/m³–

Daily means, the highest since 1 Jan 2023; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.

Use this history

SmogRank, PM2.5 monthly and daily means, Thembisa, South Africa, 1 Jan 2023 – 11 Oct 2026. Monitor data from SAAQIS (South Africa's Department of Forestry, Fisheries and the Environment) via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/za/thembisa/history (accessed 12 Oct 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Thembisa now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 21:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).