Salem Air Quality Index (AQI) & Air Pollution Today

Tamil Nadu, India — Real-time Air Quality Index (AQI) and PM2.5

Salem AQI Right Now

60

Category: Satisfactory

Dominant Pollutant: pm10

PM2.5: 31.21 µg/m³

PM10: 59.53 µg/m³

Last updated: 2026-03-24 — Data source: Google Air Quality API (NAQI). Live NAQI values load when you visit the page.

Salem Pollutant Levels

PollutantConcentration
PM2.531.21 µg/m³
PM1059.53 µg/m³
O₃ (Ozone)37.41 µg/m³
NO₂13.75 µg/m³
SO₂7.56 µg/m³
CO500.32 µg/m³

Health Advisory — Salem

Satisfactory: Minor breathing discomfort to sensitive people.

Health Impact — Salem

Cigarette Equivalent: Breathing this air is equivalent to smoking 1.4 cigarettes per day (based on current PM2.5 levels).

Life Expectancy Impact: Sustained exposure at this PM2.5 level could reduce life expectancy by 0.14 years (AQLI estimate, relative to WHO guideline of 5 µg/m³).

Health Recommendations for Salem

  • General Population: Acceptable air quality. Unusually sensitive people should limit prolonged outdoor exertion.
  • Elderly: Minor breathing discomfort is possible.
  • Children: Should be fine outdoors with normal activities.
  • Lung Disease Patients: Consider reducing prolonged outdoor exertion.

Understanding Salem Air Quality

Salem - Tamil Nadu's Steel City - sits in a distinctive semi-arid basin surrounded by the Shevaroy Hills (home to the Yercaud hill station), Nagarmalai Hills, and Kanjamalai Hills, creating a natural amphitheatre that influences local air circulation patterns. The city is India's largest cluster of steel re-rolling mills, with over 100 units along the Salem-Attur road and Suramangalam industrial area processing scrap steel into TMT bars and structural steel. These mini mills, many running on coal and furnace oil, emit significant quantities of iron oxide particulates, SO2, and carbon monoxide that give Salem's industrial zones a distinctive reddish-grey haze.

December through March is Salem's peak pollution period, coinciding with the dry northeast monsoon retreat and minimal rainfall. The semi-arid climate (annual rainfall ~850 mm, mostly from northeast monsoon) means dust is a year-round challenge, but winter months see the worst accumulation as the hill-enclosed basin reduces wind-driven dispersion. PM2.5 levels near the steel mill cluster can reach 100–160 µg/m³, while quarrying operations for magnesite, bauxite, and granite in the surrounding hills add coarse particulates that elevate PM10 levels across the city.

Salem's geographic enclosure is both a blessing and a challenge: the surrounding hills provide scenic beauty and the Yercaud forest cover acts as a regional green lung, but they also limit low-level wind flushing during calm winter months. The northeast monsoon (October–December) provides some relief, and by April, rising temperatures create thermal mixing that breaks up winter stagnation. Salem's air quality, while challenging in its industrial zones, remains moderate by all-India standards - a fact aided by Tamil Nadu's generally better regulatory enforcement and the absence of the agricultural burning that plagues northern cities.

Primary Pollution Sources

  • Vehicle exhaust
  • Steel re-rolling mill emissions
  • Road dust
  • Construction dust
  • Waste burning
  • Quarrying dust

Geography: Surrounded by Shevaroy and Nagarmalai Hills; semi-arid interior Tamil Nadu, major steel re-rolling and magnesite mining centre

Peak pollution months: December, January, February, March

Frequently Asked Questions — Salem

How do steel re-rolling mills affect Salem's air quality?

Salem's 100+ steel re-rolling mills, concentrated in the Suramangalam and Salem-Attur areas, are the city's dominant industrial pollution source. These mills heat scrap steel to 1,100–1,200°C and roll it into TMT bars, emitting iron oxide particles (visible as reddish dust), SO2, and CO. Many smaller units still use coal-fired furnaces, contributing significantly to PM2.5 levels in downwind residential areas.

Does the hilly terrain trap pollution in Salem?

Yes - Salem sits in a basin surrounded by the Shevaroy Hills, Nagarmalai, and Kanjamalai ranges, which partially restrict low-level wind flow especially during calm winter nights. This can cause localised pollutant accumulation in the city centre and industrial zones. However, during daytime, slope heating on the surrounding hills creates convective mixing that aids dispersion. The net effect is more moderate than flat-terrain Indo-Gangetic cities.

Air Quality in Nearby Cities