SmogRank / South Africa / Mpumalanga / Leslie

Leslie, month by month

Leslie has a measured daily mean on 59 days since 12 August 2026. Its worst month was September 2026, at 107 US AQI (37.8 µg/m³), 70th of 2,981 cities on that month's world ranking.

Every month since 2026

2026too few days for a mean (a year needs 200)59 days measured

JanFebMarAprMayJunJulAug20 daysSep107#70 Oct90#41

Each square is a month's mean PM2.5 in US AQI from Leslie'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 Leslie 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

1 month

Month	Why
Aug 2026	20 of 31 days measured; a month needs 22.

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

Leslie's worst months

Month	US AQI	Days measured	World rank
September 2026	10737.8 µg/m³	27 of 30	70thof 2,981

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.

Leslie's worst days

Day	US AQI
15 Aug 2026	18299.3 µg/m³
9 Sept 2026	17792.0 µg/m³
20 Aug 2026	16779.0 µg/m³
19 Aug 2026	16372.4 µg/m³
12 Sept 2026	15560.8 µg/m³
27 Aug 2026	15357.9 µg/m³
4 Sept 2026	15256.6 µg/m³
21 Aug 2026	14754.3 µg/m³
28 Aug 2026	14653.8 µg/m³
25 Sept 2026	14452.9 µg/m³

Daily means, the highest since 12 Aug 2026; 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, Leslie, South Africa, 12 Aug 2026 – 12 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/leslie/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.

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

Updated 2026-10-12 22:07 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).