Marion Air Quality Index (AQI)

Loading live AQI data...

Loading historical AQI trends...

Marion, Indiana, sits within the expansive plains of the Tipton Till Plain, a landscape sculpted by glacial activity during the last ice age. Located at coordinates 40.5497, -85.6604, the city’s terrain is generally flat, with minimal elevation changes, contributing to potential air stagnation. The Mississinewa River meanders nearby, influencing local humidity and occasionally trapping pollutants during calm weather. Marion’s position within Grant County places it within a predominantly agricultural region, surrounded by corn and soybean fields. While not a major industrial hub itself, Marion is situated within reach of larger manufacturing centers in Indiana, meaning long-range transport of pollutants is a factor. The urban-rural gradient is relatively sharp; moving just a few miles outside the city limits quickly transitions to farmland. This proximity to agricultural land introduces seasonal particulate matter from tilling and harvesting. The flat topography and limited natural barriers mean that wind patterns play a crucial role in dispersing – or concentrating – emissions. The city’s location in the Midwest exposes it to both continental air masses, bringing clean air from Canada, and warmer, more humid air from the Gulf of Mexico, which can exacerbate pollution under certain conditions. Understanding these geographical factors is key to understanding Marion’s air quality challenges.

Marion’s air quality follows a distinct seasonal pattern. Spring in Marion often sees a rise in particulate matter due to agricultural activities – plowing and planting release dust and soil particles into the air. Rainfall is moderate, offering some cleansing, but calm days can lead to localized build-up. Summer brings warmer temperatures and increased ozone formation, particularly on hot, sunny days with stagnant air. July and August are typically the months when ozone levels are highest, posing a risk to those with respiratory conditions. Autumn offers a brief respite, with cooler temperatures and increased wind speeds helping to disperse pollutants. However, burning leaves and agricultural residue can contribute to particulate matter. Winter is often the period of poorest air quality. Temperature inversions, where a layer of warm air traps cooler air near the surface, are common, concentrating pollutants from heating sources – wood stoves and vehicle emissions. December, January, and February are the months to be most cautious about outdoor activity. Sensitive groups, including children, the elderly, and those with asthma, should limit prolonged exertion outdoors during these periods. Monitoring local conditions and adjusting activity levels accordingly is crucial for protecting respiratory health.