EnviroNearby

Darlington County, South Carolina air quality history

Daily Air Quality Index summaries from EPA monitors in Darlington, South Carolina, 1980–2025.

89%
Good days in 2025
40
Median daily AQI, 2025
0
Days above 100 in 2025
254
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Darlington, South Carolina on 254 days. 226 of those days (89%) were in the Good range, and the median daily AQI was 40. That median is lower than the typical monitored county in South Carolina (median 43 across 13 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 254 days. Across the years with fuller monitoring, the share of Good days rose: an average of 55% in 1980–1982 versus 88% in 2023–2025.

EPA did not report an AQI for every day of 2025 here (254 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.

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%1980: Good 75 of 186 days1980: Moderate 46 of 186 days1980: Unhealthy for Sensitive Groups 51 of 186 days1980: Unhealthy 14 of 186 days19801981: Good 93 of 171 days1981: Moderate 52 of 171 days1981: Unhealthy for Sensitive Groups 17 of 171 days1981: Unhealthy 9 of 171 days1982: Good 93 of 135 days1982: Moderate 22 of 135 days1982: Unhealthy for Sensitive Groups 16 of 135 days1982: Unhealthy 4 of 135 days1984: Good 72 of 125 days1984: Moderate 26 of 125 days1984: Unhealthy for Sensitive Groups 17 of 125 days1984: Unhealthy 10 of 125 days1986: Good 79 of 168 days1986: Moderate 56 of 168 days1986: Unhealthy for Sensitive Groups 29 of 168 days1986: Unhealthy 4 of 168 days1988: Good 144 of 223 days1988: Moderate 50 of 223 days1988: Unhealthy for Sensitive Groups 20 of 223 days1988: Unhealthy 7 of 223 days1988: Very Unhealthy 2 of 223 days19881990: Good 110 of 204 days1990: Moderate 64 of 204 days1990: Unhealthy for Sensitive Groups 28 of 204 days1990: Unhealthy 2 of 204 days1993: Good 125 of 211 days1993: Moderate 61 of 211 days1993: Unhealthy for Sensitive Groups 24 of 211 days1993: Unhealthy 1 of 211 days1994: Good 185 of 248 days1994: Moderate 44 of 248 days1994: Unhealthy for Sensitive Groups 16 of 248 days1994: Unhealthy 3 of 248 days1995: Good 251 of 337 days1995: Moderate 82 of 337 days1995: Unhealthy for Sensitive Groups 4 of 337 days1996: Good 268 of 344 days1996: Moderate 62 of 344 days1996: Unhealthy for Sensitive Groups 14 of 344 days19961997: Good 249 of 364 days1997: Moderate 93 of 364 days1997: Unhealthy for Sensitive Groups 21 of 364 days1997: Unhealthy 1 of 364 days1998: Good 210 of 328 days1998: Moderate 73 of 328 days1998: Unhealthy for Sensitive Groups 39 of 328 days1998: Unhealthy 6 of 328 days1999: Good 239 of 359 days1999: Moderate 78 of 359 days1999: Unhealthy for Sensitive Groups 33 of 359 days1999: Unhealthy 9 of 359 days2000: Good 223 of 336 days2000: Moderate 89 of 336 days2000: Unhealthy for Sensitive Groups 20 of 336 days2000: Unhealthy 4 of 336 days2001: Good 244 of 360 days2001: Moderate 82 of 360 days2001: Unhealthy for Sensitive Groups 34 of 360 days20012002: Good 252 of 349 days2002: Moderate 64 of 349 days2002: Unhealthy for Sensitive Groups 26 of 349 days2002: Unhealthy 7 of 349 days2003: Good 291 of 358 days2003: Moderate 57 of 358 days2003: Unhealthy for Sensitive Groups 9 of 358 days2003: Unhealthy 1 of 358 days2004: Good 284 of 361 days2004: Moderate 67 of 361 days2004: Unhealthy for Sensitive Groups 9 of 361 days2004: Unhealthy 1 of 361 days2005: Good 228 of 306 days2005: Moderate 60 of 306 days2005: Unhealthy for Sensitive Groups 17 of 306 days2005: Unhealthy 1 of 306 days2006: Good 135 of 222 days2006: Moderate 76 of 222 days2006: Unhealthy for Sensitive Groups 11 of 222 days20062007: Good 163 of 248 days2007: Moderate 79 of 248 days2007: Unhealthy for Sensitive Groups 6 of 248 days2008: Good 160 of 236 days2008: Moderate 69 of 236 days2008: Unhealthy for Sensitive Groups 7 of 236 days2009: Good 267 of 288 days2009: Moderate 21 of 288 days2010: Good 259 of 321 days2010: Moderate 58 of 321 days2010: Unhealthy for Sensitive Groups 4 of 321 days2011: Good 172 of 259 days2011: Moderate 84 of 259 days2011: Unhealthy for Sensitive Groups 3 of 259 days20112012: Good 209 of 242 days2012: Moderate 30 of 242 days2012: Unhealthy for Sensitive Groups 3 of 242 days2013: Good 216 of 227 days2013: Moderate 11 of 227 days2014: Good 196 of 230 days2014: Moderate 34 of 230 days2015: Good 229 of 244 days2015: Moderate 15 of 244 days2016: Good 220 of 241 days2016: Moderate 21 of 241 days20162017: Good 254 of 274 days2017: Moderate 20 of 274 days2018: Good 133 of 142 days2018: Moderate 9 of 142 days2019: Good 110 of 122 days2019: Moderate 12 of 122 days2020: Good 253 of 253 days2021: Good 257 of 275 days2021: Moderate 18 of 275 days20212022: Good 249 of 265 days2022: Moderate 16 of 265 days2023: Good 238 of 271 days2023: Moderate 33 of 271 days2024: Good 224 of 261 days2024: Moderate 37 of 261 days2025: Good 226 of 254 days2025: Moderate 28 of 254 days2025
  • 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 year0501001501980: 90th percentile AQI 1471981: 90th percentile AQI 1151982: 90th percentile AQI 1261984: 90th percentile AQI 1431986: 90th percentile AQI 1191988: 90th percentile AQI 1121990: 90th percentile AQI 1081993: 90th percentile AQI 1051994: 90th percentile AQI 801995: 90th percentile AQI 771996: 90th percentile AQI 771997: 90th percentile AQI 901998: 90th percentile AQI 1151999: 90th percentile AQI 1052000: 90th percentile AQI 932001: 90th percentile AQI 1002002: 90th percentile AQI 1002003: 90th percentile AQI 742004: 90th percentile AQI 712005: 90th percentile AQI 802006: 90th percentile AQI 902007: 90th percentile AQI 742008: 90th percentile AQI 802009: 90th percentile AQI 482010: 90th percentile AQI 642011: 90th percentile AQI 802012: 90th percentile AQI 542013: 90th percentile AQI 472014: 90th percentile AQI 612015: 90th percentile AQI 492016: 90th percentile AQI 502017: 90th percentile AQI 492018: 90th percentile AQI 482019: 90th percentile AQI 502020: 90th percentile AQI 422021: 90th percentile AQI 482022: 90th percentile AQI 472023: 90th percentile AQI 512024: 90th percentile AQI 542025: 90th percentile AQI 511980: Median AQI 641981: Median AQI 491982: Median AQI 411984: Median AQI 471986: Median AQI 581988: Median AQI 441990: Median AQI 491993: Median AQI 481994: Median AQI 391995: Median AQI 351996: Median AQI 371997: Median AQI 411998: Median AQI 421999: Median AQI 412000: Median AQI 422001: Median AQI 422002: Median AQI 382003: Median AQI 372004: Median AQI 372005: Median AQI 412006: Median AQI 472007: Median AQI 472008: Median AQI 452009: Median AQI 352010: Median AQI 412011: Median AQI 442012: Median AQI 392013: Median AQI 362014: Median AQI 412015: Median AQI 402016: Median AQI 392017: Median AQI 392018: Median AQI 402019: Median AQI 382020: Median AQI 322021: Median AQI 352022: Median AQI 362023: Median AQI 402024: Median AQI 402025: Median AQI 40198019881996200120062011201620212025
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2025

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
Ozone254100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025254226280000405197Ozone
20242612243700004054100Ozone
2023271238330000405193Ozone
2022265249160000364784Ozone
2021275257180000354874Ozone
202025325300000324249Ozone
2019122110120000385090Ozone
201814213390000404887Ozone
2017274254200000394977Ozone
2016241220210000395087Ozone
2015244229150000404984Ozone
2014230196340000416197Ozone
2013227216110000364793Ozone
20122422093030003954147Ozone
20112591728430004480122Ozone
20103212595840004164112Ozone
2009288267210000354887Ozone
20082361606970004580136Ozone
20072481637960004774119Ozone
200622213576110004790126Ozone
200530622860171004180151Ozone
20043612846791003771151Ozone
20033582915791003774154Ozone
2002349252642670038100185Ozone
2001360244823400042100150Ozone
200033622389204004293187Ozone
1999359239783390041105172Ozone
1998328210733960042115192Ozone
199736424993211004190161Ozone
199634426862140003777150Ozone
19953372518240003577147Ozone
199424818544163003980174Ozone
1993211125612410048105159Ozone
1990204110642820049108161Ozone
1988223144502072044112207Ozone
198616879562940058119174Ozone
1984125722617100047143195Ozone
198213593221640041126177Ozone
198117193521790049115177Ozone
1980186754651140064147190Ozone

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.

Counties in South Carolina with a similar median AQI in 2025

All monitored counties in South Carolina

Source: U.S. EPA AirData, “Annual AQI by County” files for 1980–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem