SmogRank / Episodes / United States
Eastern United States, February 2024
For 2 days, from 21 to 22 February 2024, 25 cities in the United States had PM2.5 at least twice their usual for the time of year. The worst reading was Macon, Georgia, United States: 44.0 µg/m³ on 22 February, about 4.2× its usual 10.4.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 25 in 1 country
Days 2 21 to 22 February 2024
Worst day 22 February 22 cities counted
Furthest above usual 4.6× Gadsden
Day by day
Play 22 February 22 cities at twice their usual or more
Lawrenceville Forest Park Atlanta Valdosta Asheville Maryville Savannah Knoxville Brunswick Montgomery Hickory Charlotte Kingsport Jacksonville North Charleston Cookeville Fruit Cove Ponte Vedra Beach Decatur Lexington Columbia Conway Hendersonville Nashville Greensboro Midway Ferry Pass Fayetteville Clarksville Morrisville Durham Fairhope Prichard Raleigh Augusta Tallahassee Candler-McAfee Hueytown Kennesaw Spartanburg East Ridge Warner Robins Greenville Florence Phenix City Athens Albany Chattanooga Gainesville Birmingham Saint Andrews Huntsville Clemmons Macon Columbus Trussville Winston-Salem McDonough Gadsden 18 Feb 19 20 21 22 23 24 25 Every measured city in the area, coloured by its PM2.5 that day; a dark ring marks a city at twice its usual or more. Bars: cities counted each day, coloured by their median level. Choose a day or press play; without JavaScript, the days link to that day's world ranking.
How it spread
Albany Albany, 18 February: 7.9 µg/m³, 0.7× usual Albany, 19 February: 21.2 µg/m³, 2.0× usual Albany, 20 February: 43.6 µg/m³, 4.1× usual Albany, 21 February: 37.2 µg/m³, 3.5× usual Albany, 22 February: 41.7 µg/m³, 3.9× usual Albany, 23 February: 8.5 µg/m³, 0.8× usual Albany, 24 February: 7.6 µg/m³, 0.7× usual Albany, 25 February: 14.4 µg/m³, 1.3× usual Augusta Augusta, 18 February: 6.4 µg/m³, 0.6× usual Augusta, 19 February: 16.6 µg/m³, 1.5× usual Augusta, 20 February: 37.4 µg/m³, 3.4× usual Augusta, 21 February: 17.6 µg/m³, 1.6× usual Augusta, 22 February: 29.5 µg/m³, 2.7× usual Augusta, 23 February: 9.0 µg/m³, 0.8× usual Augusta, 24 February: 3.0 µg/m³, 0.3× usual Augusta, 25 February: 6.3 µg/m³, 0.6× usual Macon Macon, 18 February: 16.3 µg/m³, 1.6× usual Macon, 19 February: 16.9 µg/m³, 1.6× usual Macon, 20 February: 30.8 µg/m³, 3.0× usual Macon, 21 February: 31.3 µg/m³, 3.0× usual Macon, 22 February: 44.0 µg/m³, 4.2× usual Macon, 23 February: 8.6 µg/m³, 0.8× usual Macon, 24 February: 6.9 µg/m³, 0.7× usual Macon, 25 February: 9.9 µg/m³, 1.0× usual Birmingham Birmingham, 18 February: 6.1 µg/m³, 0.6× usual Birmingham, 19 February: 11.4 µg/m³, 1.2× usual Birmingham, 20 February: 22.3 µg/m³, 2.3× usual Birmingham, 21 February: 39.6 µg/m³, 4.0× usual Birmingham, 22 February: 28.0 µg/m³, 2.9× usual Birmingham, 23 February: 6.0 µg/m³, 0.6× usual Birmingham, 24 February: 7.0 µg/m³, 0.7× usual Birmingham, 25 February: 18.7 µg/m³, 1.9× usual Columbus Columbus, 18 February: 8.0 µg/m³, 0.8× usual Columbus, 19 February: 11.2 µg/m³, 1.2× usual Columbus, 20 February: 17.5 µg/m³, 1.8× usual Columbus, 21 February: 36.2 µg/m³, 3.7× usual Columbus, 22 February: 42.1 µg/m³, 4.3× usual Columbus, 23 February: 6.1 µg/m³, 0.6× usual Columbus, 24 February: 5.5 µg/m³, 0.6× usual Columbus, 25 February: 14.4 µg/m³, 1.5× usual Trussville Trussville, 18 February: 6.6 µg/m³, 0.8× usual Trussville, 19 February: 7.3 µg/m³, 0.9× usual Trussville, 20 February: 14.1 µg/m³, 1.7× usual Trussville, 21 February: 34.5 µg/m³, 4.3× usual Trussville, 22 February: 22.4 µg/m³, 2.8× usual Trussville, 23 February: 4.9 µg/m³, 0.6× usual Trussville, 24 February: 5.4 µg/m³, 0.7× usual Trussville, 25 February: 11.5 µg/m³, 1.4× usual Gadsden Gadsden, 18 February: 5.4 µg/m³, 0.8× usual Gadsden, 19 February: 6.5 µg/m³, 0.9× usual Gadsden, 20 February: 12.5 µg/m³, 1.8× usual Gadsden, 21 February: 31.7 µg/m³, 4.6× usual Gadsden, 22 February: 25.3 µg/m³, 3.7× usual Gadsden, 23 February: 4.8 µg/m³, 0.7× usual Gadsden, 24 February: 4.7 µg/m³, 0.7× usual Gadsden, 25 February: 8.2 µg/m³, 1.2× usual Phenix City Phenix City, 18 February: 6.2 µg/m³, 0.7× usual Phenix City, 19 February: 8.5 µg/m³, 0.9× usual Phenix City, 20 February: 16.2 µg/m³, 1.8× usual Phenix City, 21 February: 31.0 µg/m³, 3.4× usual Phenix City, 22 February: 34.5 µg/m³, 3.8× usual Phenix City, 23 February: 6.1 µg/m³, 0.7× usual Phenix City, 24 February: 4.7 µg/m³, 0.5× usual Phenix City, 25 February: 10.6 µg/m³, 1.2× usual Florence Florence, 18 February: 5.0 µg/m³, 0.6× usual Florence, 19 February: 7.0 µg/m³, 0.9× usual Florence, 20 February: 8.6 µg/m³, 1.1× usual Florence, 21 February: 30.1 µg/m³, 3.8× usual Florence, 22 February: 29.2 µg/m³, 3.7× usual Florence, 23 February: 9.8 µg/m³, 1.2× usual Florence, 24 February: 3.8 µg/m³, 0.5× usual Florence, 25 February: 4.5 µg/m³, 0.6× usual Huntsville Huntsville, 18 February: 5.2 µg/m³, 0.7× usual Huntsville, 19 February: 9.7 µg/m³, 1.4× usual Huntsville, 20 February: 12.4 µg/m³, 1.7× usual Huntsville, 21 February: 29.3 µg/m³, 4.1× usual Huntsville, 22 February: 21.2 µg/m³, 3.0× usual Huntsville, 23 February: 4.1 µg/m³, 0.6× usual Huntsville, 24 February: 3.7 µg/m³, 0.5× usual Huntsville, 25 February: 9.0 µg/m³, 1.3× usual Hueytown Hueytown, 18 February: no reading Hueytown, 19 February: no reading Hueytown, 20 February: no reading Hueytown, 21 February: 28.0 µg/m³, 3.3× usual Hueytown, 22 February: 21.1 µg/m³, 2.5× usual Hueytown, 23 February: 5.3 µg/m³, 0.6× usual Hueytown, 24 February: 6.5 µg/m³, 0.8× usual Hueytown, 25 February: 10.8 µg/m³, 1.3× usual East Ridge East Ridge, 18 February: 7.7 µg/m³, 0.8× usual East Ridge, 19 February: 10.6 µg/m³, 1.1× usual East Ridge, 20 February: 18.3 µg/m³, 1.9× usual East Ridge, 21 February: 26.9 µg/m³, 2.8× usual East Ridge, 22 February: 33.3 µg/m³, 3.5× usual East Ridge, 23 February: 5.0 µg/m³, 0.5× usual East Ridge, 24 February: 4.3 µg/m³, 0.4× usual East Ridge, 25 February: 16.7 µg/m³, 1.7× usual Gainesville Gainesville, 18 February: 5.5 µg/m³, 0.6× usual Gainesville, 19 February: 4.9 µg/m³, 0.6× usual Gainesville, 20 February: 16.1 µg/m³, 1.9× usual Gainesville, 21 February: 26.3 µg/m³, 3.0× usual Gainesville, 22 February: 34.5 µg/m³, 4.0× usual Gainesville, 23 February: 8.2 µg/m³, 0.9× usual Gainesville, 24 February: 3.2 µg/m³, 0.4× usual Gainesville, 25 February: 5.7 µg/m³, 0.7× usual Athens Athens, 18 February: 5.3 µg/m³, 0.7× usual Athens, 19 February: 8.5 µg/m³, 1.1× usual Athens, 20 February: 19.4 µg/m³, 2.6× usual Athens, 21 February: 25.1 µg/m³, 3.3× usual Athens, 22 February: 29.4 µg/m³, 3.9× usual Athens, 23 February: 6.0 µg/m³, 0.8× usual Athens, 24 February: 2.8 µg/m³, 0.4× usual Athens, 25 February: 9.6 µg/m³, 1.3× usual Warner Robins Warner Robins, 18 February: 14.6 µg/m³, 1.6× usual Warner Robins, 19 February: 12.0 µg/m³, 1.3× usual Warner Robins, 20 February: 21.8 µg/m³, 2.3× usual Warner Robins, 21 February: 25.0 µg/m³, 2.7× usual Warner Robins, 22 February: 34.3 µg/m³, 3.6× usual Warner Robins, 23 February: 8.5 µg/m³, 0.9× usual Warner Robins, 24 February: 3.8 µg/m³, 0.4× usual Warner Robins, 25 February: 7.9 µg/m³, 0.8× usual Greenville Greenville, 18 February: 7.7 µg/m³, 0.9× usual Greenville, 19 February: 7.4 µg/m³, 0.8× usual Greenville, 20 February: 14.8 µg/m³, 1.7× usual Greenville, 21 February: 19.3 µg/m³, 2.2× usual Greenville, 22 February: 33.0 µg/m³, 3.7× usual Greenville, 23 February: 15.7 µg/m³, 1.8× usual Greenville, 24 February: 2.7 µg/m³, 0.3× usual Greenville, 25 February: 5.6 µg/m³, 0.6× usual Spartanburg Spartanburg, 18 February: 6.3 µg/m³, 0.7× usual Spartanburg, 19 February: 10.6 µg/m³, 1.2× usual Spartanburg, 20 February: 15.5 µg/m³, 1.7× usual Spartanburg, 21 February: 19.9 µg/m³, 2.2× usual Spartanburg, 22 February: 32.5 µg/m³, 3.5× usual Spartanburg, 23 February: 17.9 µg/m³, 1.9× usual Spartanburg, 24 February: 3.3 µg/m³, 0.4× usual Spartanburg, 25 February: 6.4 µg/m³, 0.7× usual Chattanooga Chattanooga, 18 February: 4.3 µg/m³, 0.6× usual Chattanooga, 19 February: 4.9 µg/m³, 0.6× usual Chattanooga, 20 February: 10.0 µg/m³, 1.3× usual Chattanooga, 21 February: 20.7 µg/m³, 2.7× usual Chattanooga, 22 February: 30.1 µg/m³, 4.0× usual Chattanooga, 23 February: 4.6 µg/m³, 0.6× usual Chattanooga, 24 February: 3.5 µg/m³, 0.5× usual Chattanooga, 25 February: 13.8 µg/m³, 1.8× usual Saint Andrews Saint Andrews, 18 February: 6.6 µg/m³, 0.9× usual Saint Andrews, 19 February: 9.7 µg/m³, 1.3× usual Saint Andrews, 20 February: 9.1 µg/m³, 1.2× usual Saint Andrews, 21 February: 11.0 µg/m³, 1.5× usual Saint Andrews, 22 February: 29.8 µg/m³, 4.1× usual Saint Andrews, 23 February: 13.2 µg/m³, 1.8× usual Saint Andrews, 24 February: 4.0 µg/m³, 0.5× usual Saint Andrews, 25 February: 4.7 µg/m³, 0.6× usual Winston-Salem Winston-Salem, 18 February: 5.5 µg/m³, 0.8× usual Winston-Salem, 19 February: 5.5 µg/m³, 0.8× usual Winston-Salem, 20 February: 8.7 µg/m³, 1.3× usual Winston-Salem, 21 February: 11.3 µg/m³, 1.7× usual Winston-Salem, 22 February: 28.9 µg/m³, 4.4× usual Winston-Salem, 23 February: 23.9 µg/m³, 3.7× usual Winston-Salem, 24 February: 3.9 µg/m³, 0.6× usual Winston-Salem, 25 February: 4.5 µg/m³, 0.7× usual Clemmons Clemmons, 18 February: 5.3 µg/m³, 0.8× usual Clemmons, 19 February: 6.1 µg/m³, 0.9× usual Clemmons, 20 February: 10.2 µg/m³, 1.6× usual Clemmons, 21 February: 11.3 µg/m³, 1.7× usual Clemmons, 22 February: 27.3 µg/m³, 4.2× usual Clemmons, 23 February: 23.5 µg/m³, 3.6× usual Clemmons, 24 February: 3.4 µg/m³, 0.5× usual Clemmons, 25 February: 4.6 µg/m³, 0.7× usual Tallahassee Tallahassee, 18 February: 5.8 µg/m³, 0.7× usual Tallahassee, 19 February: 8.5 µg/m³, 1.0× usual Tallahassee, 20 February: 14.8 µg/m³, 1.7× usual Tallahassee, 21 February: 21.0 µg/m³, 2.4× usual Tallahassee, 22 February: 27.3 µg/m³, 3.1× usual Tallahassee, 23 February: 8.2 µg/m³, 0.9× usual Tallahassee, 24 February: 5.7 µg/m³, 0.6× usual Tallahassee, 25 February: 7.6 µg/m³, 0.9× usual Kennesaw Kennesaw, 18 February: 6.9 µg/m³, 0.9× usual Kennesaw, 19 February: 9.7 µg/m³, 1.2× usual Kennesaw, 20 February: 16.9 µg/m³, 2.1× usual Kennesaw, 21 February: 21.7 µg/m³, 2.7× usual Kennesaw, 22 February: 27.0 µg/m³, 3.4× usual Kennesaw, 23 February: 5.4 µg/m³, 0.7× usual Kennesaw, 24 February: 3.6 µg/m³, 0.5× usual Kennesaw, 25 February: 6.4 µg/m³, 0.8× usual Candler-McAfee Candler-McAfee, 18 February: 5.2 µg/m³, 0.6× usual Candler-McAfee, 19 February: 6.6 µg/m³, 0.8× usual Candler-McAfee, 20 February: 19.8 µg/m³, 2.4× usual Candler-McAfee, 21 February: 16.6 µg/m³, 2.0× usual Candler-McAfee, 22 February: 26.5 µg/m³, 3.2× usual Candler-McAfee, 23 February: 5.7 µg/m³, 0.7× usual Candler-McAfee, 24 February: 3.1 µg/m³, 0.4× usual Candler-McAfee, 25 February: 7.2 µg/m³, 0.9× usual McDonough McDonough, 18 February: 4.5 µg/m³, 0.8× usual McDonough, 19 February: 4.8 µg/m³, 0.8× usual McDonough, 20 February: 12.8 µg/m³, 2.2× usual McDonough, 21 February: 19.5 µg/m³, 3.4× usual McDonough, 22 February: 25.7 µg/m³, 4.4× usual McDonough, 23 February: 5.7 µg/m³, 1.0× usual McDonough, 24 February: 2.9 µg/m³, 0.5× usual McDonough, 25 February: 4.6 µg/m³, 0.8× usual 18 Feb 19 20 21 22 23 24 25 Every counted city, in the order the episode reached them, 3 days before to 3 after. Each square is a day, coloured by that day's PM2.5; outlined: at twice the city's usual or more. Good 0–50
Moderate 51–100
Sensitive groups 101–150
Unhealthy 151–200
Very unhealthy 201–300
Hazardous 301+
Every city it reached
City Days Highest Usual Above usual
Gadsden Alabama, United States 2 21 February 6.9 4.6× Winston-Salem North Carolina, United States 1 22 February 6.5 4.4× McDonough Georgia, United States 1 22 February 5.8 4.4× Columbus Georgia, United States 2 22 February 9.7 4.3× Trussville Alabama, United States 1 21 February 8.1 4.3× Macon Georgia, United States 2 22 February 10.4 4.2× Clemmons North Carolina, United States 1 22 February 6.5 4.2× Huntsville Alabama, United States 1 21 February 7.1 4.1× Saint Andrews South Carolina, United States 1 22 February 7.3 4.1× Albany Georgia, United States 2 20 February 10.7 4.1× Birmingham Alabama, United States 2 21 February 9.8 4.0× Gainesville Georgia, United States 2 22 February 8.7 4.0× Chattanooga Tennessee, United States 1 22 February 7.6 4.0× Athens Georgia, United States 2 22 February 7.5 3.9× Florence South Carolina, United States 2 21 February 7.9 3.8× Phenix City Alabama, United States 2 22 February 9.1 3.8× Greenville South Carolina, United States 1 22 February 8.8 3.7× Warner Robins Georgia, United States 2 22 February 9.4 3.6× Spartanburg South Carolina, United States 1 22 February 9.2 3.5× East Ridge Tennessee, United States 2 22 February 9.6 3.5× Kennesaw Georgia, United States 1 22 February 7.9 3.4× Augusta Georgia, United States 1 20 February 11.1 3.4× Hueytown Alabama, United States 1 21 February 8.5 3.3× Candler-McAfee Georgia, United States 1 22 February 8.4 3.2× Tallahassee Florida, United States 1 22 February 8.9 3.1×
Daily means in µg/m³. Usual: the city's median for this time of year (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that.
Against other episodes in the United States
Number 41 of 131 episodes in the United States since our records began, by cities reached.
North-eastern United States and Canada, June and July 2023 280 North-eastern United States and Canada, July 2026 264 North-eastern United States and Canada, May and June 2023 261 North-eastern United States and Canada, July and August 2025 241 North-eastern United States and Canada, July 2023 240 North-eastern United States and Canada, June 2025 196 North-eastern United States and Canada, June 2023 161 North-eastern United States and Canada, July 2025 119 North-western United States and Canada, August 2023 110 North-eastern United States, June 2025 104 North-western United States and Canada, August 2026 99 North-eastern United States and Canada, February 2026 96 Eastern United States, February 2024 25 Bars: cities reached; colour: the level of the episode's highest daily reading. All 131 .
Use this page SmogRank, Eastern United States, February 2024: 25 cities with PM2.5 at twice their usual or more, 21 to 22 February 2024, smogrank.com/episodes/2024-02-eastern-united-states (accessed 3 October 2026).
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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms .
An episode is a run of days when many cities close to each other (four or more within 350 km on a day, 8 or more in all) each had a daily PM2.5 mean of at least 25 µg/m³ and at least 2 times their usual for that time of year. Found in our own measurements, not picked by hand. How we find episodes . Values are each city's daily mean of its own monitors; causes are the usual kinds for a pattern like this, not a confirmed source.
