EnviroNearby

Panola County, Mississippi air quality history

Daily Air Quality Index summaries from EPA monitors in Panola, Mississippi, 1998–1999.

54%
Good days in 1998
48
Median daily AQI, 1998
44
Days above 100 in 1998
272
Days with an AQI in 1998 (of 365)

In 1998, EPA reported a daily Air Quality Index (AQI) for Panola, Mississippi on 272 days. 148 of those days (54%) were in the Good range, and the median daily AQI was 48. That median is higher than the typical monitored county in Mississippi (median 45 across 11 counties), and higher than the typical monitored U.S. county (41). The main pollutant was ozone on 257 days.

EPA did not report an AQI for every day of 1998 here (272 of 365 days). Figures describe monitored days only; seasonal monitoring (for example, ozone measured only in warmer months) can make a county look cleaner or dirtier than a full-year record would.

The most recent year with data for this county is 1999; EPA's files for 2000–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (1999) are shown in the table but left out of comparisons and trend statements.

How the days broke down each year

Each bar is one year. The colored segments show the share of monitored days that fell in each AQI category.

Share of monitored days in each AQI category, by year0%25%50%75%100%1998: Good 148 of 272 days1998: Moderate 80 of 272 days1998: Unhealthy for Sensitive Groups 32 of 272 days1998: Unhealthy 12 of 272 days19981999: Good 78 of 83 days1999: Moderate 5 of 83 days1999
  • Good
  • Moderate
  • Unhealthy for Sensitive Groups
  • Unhealthy
  • Very Unhealthy
  • Hazardous

Typical and high-end AQI over time

The median is the middle day of the year. The 90th percentile is the level that only the highest 10% of days exceeded.

Median and 90th-percentile daily AQI, by year0501001501998: 90th percentile AQI 1291999: 90th percentile AQI 461998: Median AQI 481999: Median AQI 3619981999
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 1998

On each monitored day, the AQI reflects whichever measured pollutant had the highest index. This counts how many days each pollutant set the AQI. A pollutant that was not measured here cannot appear.

PollutantDays as main pollutantShare of monitored days
Ozone25794%
Nitrogen dioxide (NO₂)135%
Coarse particles (PM10)21%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
1999837850000364677Ozone
19982721488032120048129169Ozone

What this data can and can’t tell you

It is a county-level summary. EPA reports one AQI per day for the county, based on the monitors operating there. Air at a particular street, school or home can differ, especially near roads, industry or wildfire smoke.

It is not a health assessment. The AQI is EPA’s scale for communicating daily air quality. A county’s history can’t tell you what the health risk is for any particular person. For daily conditions and health guidance, see AirNow.

Rules change over time. EPA has revised AQI breakpoints, most recently for fine particles in 2024, so some year-to-year change can reflect the scale rather than the air.

All monitored counties in Mississippi

Source: U.S. EPA AirData, “Annual AQI by County” files for 1998–1999 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem