EnviroNearby

Sullivan County, New Hampshire air quality history

Daily Air Quality Index summaries from EPA monitors in Sullivan, New Hampshire, 1990–2008.

84%
Good days in 2008
36
Median daily AQI, 2008
1
Days above 100 in 2008
212
Days with an AQI in 2008 (of 366)

In 2008, EPA reported a daily Air Quality Index (AQI) for Sullivan, New Hampshire on 212 days. 179 of those days (84%) were in the Good range, and the median daily AQI was 36. That median is lower than the typical monitored county in New Hampshire (median 38.5 across 8 counties), and lower than the typical monitored U.S. county (44). The main pollutant was ozone on 165 days. Across the years with fuller monitoring, the share of Good days fell: an average of 92% in 1990–1992 versus 82% in 2006–2008.

EPA did not report an AQI for every day of 2008 here (212 of 366 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 2008; EPA's files for 2009–2025 contain no row for it, which usually means its monitors stopped reporting.

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%1990: Good 217 of 236 days1990: Moderate 17 of 236 days1990: Unhealthy for Sensitive Groups 2 of 236 days19901991: Good 218 of 242 days1991: Moderate 19 of 242 days1991: Unhealthy for Sensitive Groups 4 of 242 days1991: Unhealthy 1 of 242 days1992: Good 219 of 233 days1992: Moderate 10 of 233 days1992: Unhealthy for Sensitive Groups 4 of 233 days19921993: Good 221 of 236 days1993: Moderate 11 of 236 days1993: Unhealthy for Sensitive Groups 3 of 236 days1993: Unhealthy 1 of 236 days1994: Good 212 of 232 days1994: Moderate 17 of 232 days1994: Unhealthy for Sensitive Groups 2 of 232 days1994: Unhealthy 1 of 232 days19941995: Good 202 of 225 days1995: Moderate 18 of 225 days1995: Unhealthy for Sensitive Groups 5 of 225 days1996: Good 210 of 227 days1996: Moderate 14 of 227 days1996: Unhealthy for Sensitive Groups 2 of 227 days1996: Unhealthy 1 of 227 days19961997: Good 193 of 211 days1997: Moderate 13 of 211 days1997: Unhealthy for Sensitive Groups 4 of 211 days1997: Unhealthy 1 of 211 days1998: Good 215 of 234 days1998: Moderate 17 of 234 days1998: Unhealthy for Sensitive Groups 2 of 234 days19981999: Good 176 of 229 days1999: Moderate 45 of 229 days1999: Unhealthy for Sensitive Groups 8 of 229 days2000: Good 209 of 241 days2000: Moderate 30 of 241 days2000: Unhealthy for Sensitive Groups 1 of 241 days2000: Unhealthy 1 of 241 days20002001: Good 155 of 205 days2001: Moderate 45 of 205 days2001: Unhealthy for Sensitive Groups 5 of 205 days2002: Good 159 of 211 days2002: Moderate 44 of 211 days2002: Unhealthy for Sensitive Groups 4 of 211 days2002: Unhealthy 4 of 211 days20022003: Good 156 of 208 days2003: Moderate 47 of 208 days2003: Unhealthy for Sensitive Groups 5 of 208 days2004: Good 167 of 212 days2004: Moderate 39 of 212 days2004: Unhealthy for Sensitive Groups 5 of 212 days2004: Unhealthy 1 of 212 days20042005: Good 162 of 211 days2005: Moderate 46 of 211 days2005: Unhealthy for Sensitive Groups 3 of 211 days2006: Good 176 of 212 days2006: Moderate 36 of 212 days20062007: Good 166 of 211 days2007: Moderate 39 of 211 days2007: Unhealthy for Sensitive Groups 6 of 211 days2008: Good 179 of 212 days2008: Moderate 32 of 212 days2008: Unhealthy for Sensitive Groups 1 of 212 days2008
  • 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 year0501001990: 90th percentile AQI 471991: 90th percentile AQI 491992: 90th percentile AQI 451993: 90th percentile AQI 461994: 90th percentile AQI 501995: 90th percentile AQI 511996: 90th percentile AQI 481997: 90th percentile AQI 491998: 90th percentile AQI 491999: 90th percentile AQI 642000: 90th percentile AQI 542001: 90th percentile AQI 672002: 90th percentile AQI 712003: 90th percentile AQI 672004: 90th percentile AQI 652005: 90th percentile AQI 612006: 90th percentile AQI 572007: 90th percentile AQI 642008: 90th percentile AQI 551990: Median AQI 311991: Median AQI 311992: Median AQI 311993: Median AQI 301994: Median AQI 341995: Median AQI 341996: Median AQI 321997: Median AQI 321998: Median AQI 321999: Median AQI 402000: Median AQI 322001: Median AQI 402002: Median AQI 402003: Median AQI 422004: Median AQI 382005: Median AQI 402006: Median AQI 382007: Median AQI 372008: Median AQI 361990199219941996199820002002200420062008
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2008

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
Ozone16578%
Fine particles (PM2.5)4722%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20082121793210003655129Ozone
20072111663960003764133Ozone
20062121763600003857100Ozone
20052111624630004061133Ozone
20042121673951003865174Ozone
20032081564750004267147Ozone
20022111594444004071172Ozone
20012051554550004067143Ozone
20002412093011003254159Ozone
19992291764580004064147Ozone
19982342151720003249115Ozone
19972111931341003249156Ozone
19962272101421003248151Ozone
19952252021850003451126Ozone
19942322121721003450151Ozone
19932362211131003046161Ozone
19922332191040003145133Ozone
19912422181941003149156Ozone
19902362171720003147143Ozone

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 New Hampshire

Source: U.S. EPA AirData, “Annual AQI by County” files for 1990–2008 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem