SmogRank / Episodes / United States

Washington, United States, July 2023

For 1 day, on 5 July 2023, 12 cities in the United States had PM2.5 at least twice their usual for the time of year. The worst reading was Parkland, Washington, United States: 144.0 µg/m³ on 5 July, about 29× its usual 3.0. Ended 5 July.

Likely Independence Day fireworksIt came on 4 and 5 July, when fireworks smoke fills the air over many US cities at once.
Cities reached12in 1 country
Days15 July 2023
Worst day5 July12 cities counted
Furthest above usual29×Parkland

Day by day

5 July 12 cities at twice their usual or more
LaceyLongviewEnumclawRidgefieldSalmon CreekBellevueOrchardsIssaquahMill PlainNorth PortlandPortlandAberdeenBeavertonHillsboroGreshamMilwaukieForest GroveTigardPort TownsendCanbyMarysvilleHood RiverWoodburnMcMinnvilleOak HarborPort AngelesSilvertonMount VernonSalemAnacortesThe DallesVictoriaDallasStaytonLangfordBellinghamAlbanyEllensburgYakimaCorvallisLyndenSweet HomeDuncanToppenishNorth CowichanAbbotsfordLangleyDeltaStrawberry HillWenatcheeMadrasSunnysideHarewoodRedmondQuincyProsserPrinevilleEphrataMoses LakeHermistonTri-CitiesPascoFinleyPendletonWalla WallaWhite CenterVancouverShorelineSheltonAuburnChehalisCentraliaSeattleBremertonRentonTacomaParkland
2 Jul345678
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

ParklandParkland, 2 July: 3.6 µg/m³Parkland, 3 July: 7.2 µg/m³Parkland, 4 July: 53.3 µg/m³Parkland, 5 July: 144.0 µg/m³, 29× its usual 3.0Parkland, 6 July: 11.3 µg/m³Parkland, 7 July: 4.4 µg/m³Parkland, 8 July: 2.7 µg/m³TacomaTacoma, 2 July: 2.2 µg/m³Tacoma, 3 July: 6.4 µg/m³Tacoma, 4 July: 19.8 µg/m³Tacoma, 5 July: 54.8 µg/m³, 11× its usual 4.4Tacoma, 6 July: 10.7 µg/m³Tacoma, 7 July: 4.2 µg/m³Tacoma, 8 July: 2.5 µg/m³RentonRenton, 2 July: 4.5 µg/m³Renton, 3 July: 6.8 µg/m³Renton, 4 July: 23.2 µg/m³Renton, 5 July: 48.9 µg/m³, 9.8× its usual 4.6Renton, 6 July: 15.4 µg/m³Renton, 7 July: 5.6 µg/m³Renton, 8 July: 5.2 µg/m³BremertonBremerton, 2 July: 2.5 µg/m³Bremerton, 3 July: 5.7 µg/m³Bremerton, 4 July: 24.8 µg/m³Bremerton, 5 July: 31.8 µg/m³, 6.4× its usual 3.8Bremerton, 6 July: 13.3 µg/m³Bremerton, 7 July: 3.8 µg/m³Bremerton, 8 July: 3.0 µg/m³SeattleSeattle, 2 July: 4.4 µg/m³Seattle, 3 July: 6.8 µg/m³Seattle, 4 July: 13.7 µg/m³Seattle, 5 July: 31.0 µg/m³, 6.2× its usual 5.0Seattle, 6 July: 15.0 µg/m³Seattle, 7 July: 5.5 µg/m³Seattle, 8 July: 4.4 µg/m³CentraliaCentralia, 2 July: 2.5 µg/m³Centralia, 3 July: 3.8 µg/m³Centralia, 4 July: 15.3 µg/m³Centralia, 5 July: 30.7 µg/m³, 6.1× its usual 3.3Centralia, 6 July: 5.9 µg/m³Centralia, 7 July: 3.8 µg/m³Centralia, 8 July: 3.2 µg/m³ChehalisChehalis, 2 July: 2.5 µg/m³Chehalis, 3 July: 3.8 µg/m³Chehalis, 4 July: 15.3 µg/m³Chehalis, 5 July: 30.7 µg/m³, 6.1× its usual 3.3Chehalis, 6 July: 5.9 µg/m³Chehalis, 7 July: 3.8 µg/m³Chehalis, 8 July: 3.2 µg/m³AuburnAuburn, 2 July: 4.1 µg/m³Auburn, 3 July: 5.8 µg/m³Auburn, 4 July: 16.7 µg/m³Auburn, 5 July: 30.6 µg/m³, 6.1× its usual 4.7Auburn, 6 July: 18.8 µg/m³Auburn, 7 July: 5.6 µg/m³Auburn, 8 July: 3.8 µg/m³SheltonShelton, 2 July: 3.1 µg/m³Shelton, 3 July: 4.0 µg/m³Shelton, 4 July: 13.8 µg/m³Shelton, 5 July: 30.2 µg/m³, 6.0× its usual 3.4Shelton, 6 July: 6.1 µg/m³Shelton, 7 July: 3.3 µg/m³Shelton, 8 July: 3.0 µg/m³ShorelineShoreline, 2 July: 3.2 µg/m³Shoreline, 3 July: 4.3 µg/m³Shoreline, 4 July: 10.6 µg/m³Shoreline, 5 July: 29.9 µg/m³, 6.0× its usual 3.9Shoreline, 6 July: 15.7 µg/m³Shoreline, 7 July: 5.4 µg/m³Shoreline, 8 July: 3.5 µg/m³White CenterWhite Center, 2 July: 5.5 µg/m³White Center, 3 July: 7.5 µg/m³White Center, 4 July: 22.3 µg/m³White Center, 5 July: 29.7 µg/m³, 5.2× its usual 5.7White Center, 6 July: 15.0 µg/m³White Center, 7 July: 6.4 µg/m³White Center, 8 July: 5.3 µg/m³VancouverVancouver, 2 July: 3.5 µg/m³Vancouver, 3 July: 5.3 µg/m³Vancouver, 4 July: 17.5 µg/m³Vancouver, 5 July: 26.4 µg/m³, 5.3× its usual 3.3Vancouver, 6 July: 9.2 µg/m³Vancouver, 7 July: 6.8 µg/m³Vancouver, 8 July: 3.8 µg/m³2 Jul345678
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.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

Every city it reached

CityDaysHighestUsualAbove usual
ParklandWashington, United States1 144.05 July3.029×
TacomaWashington, United States1 54.85 July4.411×
RentonWashington, United States1 48.95 July4.69.8×
BremertonWashington, United States1 31.85 July3.86.4×
SeattleWashington, United States1 31.05 July5.06.2×
CentraliaWashington, United States1 30.75 July3.36.1×
ChehalisWashington, United States1 30.75 July3.36.1×
AuburnWashington, United States1 30.65 July4.76.1×
SheltonWashington, United States1 30.25 July3.46.0×
ShorelineWashington, United States1 29.95 July3.96.0×
VancouverWashington, United States1 26.45 July3.35.3×
White CenterWashington, United States1 29.75 July5.75.2×

Daily means in µg/m³, over the days each city counted in this episode. Highest: its highest of those days. Usual: the city's median for the time of year of that day (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that, with a usual under 5 µg/m³ taken as 5.

Against other episodes in the United States

Number 104 of 151 episodes in the United States since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 151.

Use this page

SmogRank, Washington, United States, July 2023: 12 cities with PM2.5 at twice their usual or more, 5 July 2023, smogrank.com/episodes/2023-07-washington-united-states (accessed 5 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.