Median AQI
37
Good
Florida · County air quality · 2025
Alachua County, Florida
Median AQI 37 (Good). 88.7% of monitored days rated Good, direct from EPA Air Quality System stations.
- 37
- Median AQI
- 88.7%
- Good-air days
- 0
- Unhealthy days
- 77%
- Cleaner than US counties
Alachua County's 2025 annual median AQI is 37 (Good), with 88.7% Good days
According to the U.S. EPA Air Quality System, Alachua County, Florida posted a 2025 median AQI of 37 (Good) across 364 monitored days, with 88.7% rated Good and 0 unhealthy or worse. This is an annual comparison, not today's advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US
- Alachua County's 88.7% Good-day share places it cleaner than 77% of US counties in 2025.
- Closest median-AQI peer
- Arlington County (87.4% Good, median AQI 37) is the closest nationwide median-AQI peer to Alachua County.
- 2020–2025 trend
- Alachua County's floor-qualifying Good-day share is improving from 2020 to 2025 (74.9% → 88.7%).
- Median AQI
- Median AQI: 37
The verdict
According to EPA Air Quality System monitoring data, Alachua County's air is good on balance, cleaner than most US counties, a median AQI of 37 with 88.7% of 364 monitored days in the Good band, driven mainly by PM2.5.
- 37
- median AQI · Good
- 88.7%
- days rated Good
- PM2.5
- main pollutant
- 77%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 69.
Annual release change
What changed in the 2025 EPA annual release
- Alachua County's Good-day share rose from 86.0% to 88.7% between the 2024 and 2025 EPA annual releases, a change of +2.8 percentage points.
- Alachua County's peak single-day AQI fell from 94 to 69 between the 2024 and 2025 EPA annual releases, a change of -25 points.
Data updated August 2026
- Good · 323 d · 88.7%
- Moderate · 41 d · 11.3%
How did Alachua County's air break down in 2025?
Across 364 monitored days, 323 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 69 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 364 days monitored. Median AQI: 37 (Good).
Insights: Alachua County, Florida. EPA monitors recorded a median Air Quality Index of 37 across 364 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 323 (89%) fell in the Good band (AQI 0–50), 41 (11%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 51, while the worst single-day peak hit 69 (Moderate). Residents averaged about 26.6 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (191 days), Ozone (173 days). Across the 2020–2025 trend window, the share of monitored days rated Good shifted by +13.9 points and the median AQI moved -5 points, placing the multi-year trajectory at improving. The worst single reading over the 2020–2025 window was AQI 69, moderate but never Unhealthy. Nearby counties show comparable readings: Baker (69.5% good, AQI 44); Bay (66.4% good, AQI 44); Brevard (91.2% good, AQI 38); Broward (73.4% good, AQI 43); Citrus (71.1% good, AQI 43); Collier (72.0% good, AQI 43).
Air Quality Summary
Good Days
88.7%
323 of 364 monitored days
13.7pp vs 75% target
Max AQI Recorded
69
Moderate
Health Grade
Good
90th-pct AQI 51
Alachua County, Good days share 88.7%
National avg
Share of monitored days at AQI 0-50 (Good band).
Alachua County, Unhealthy-or-worse share 0.0%
National avg
Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).
AQI Day Breakdown (2025)
Distribution of 364 monitored days across EPA AQI categories.
Good
323
89%
Moderate
41
11%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Alachua County.
- PM2.5 · 191 days · 52.5%
- Ozone · 173 days · 47.5%
Health Impact Assessment
Good
Alachua County's air quality is rated Good based on 88.7% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 88.7% of monitored days in 2025, with a median AQI of 37. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 191 of 364 monitored days.
5-Year Air Quality Trend
Air quality is improving in Alachua County. Highest Good-day share: 2025 (88.7%, 323 of 364 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 274 | 91 | 1 | 0 | 42 | 105 |
| 2021 | 308 | 56 | 0 | 0 | 39 | 84 |
| 2022 | 292 | 70 | 0 | 0 | 41 | 84 |
| 2023 | 270 | 94 | 1 | 0 | 40 | 104 |
| 2024 | 300 | 49 | 0 | 0 | 38 | 94 |
| 2025 | 323 | 41 | 0 | 0 | 37 | 69 |
How does Alachua County compare?
How Alachua County compares
Good-day share better than typical
Alachua County 88.7%
Arlington County, Virginia 87.4%
Typical US county 76.0%
Median AQI better than typical
Alachua County 37
Arlington County, Virginia 37
Typical US county 39
Unhealthy days / yr better than typical
Alachua County 0
Arlington County, Virginia 0
Typical US county 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as Alachua County (37), not geographic neighbors.
Arlington County, Virginia
Median AQI 37 · 87.4% Good-day share
Bennington County, Vermont
Median AQI 37 · 83.6% Good-day share
Boone County, Missouri
Median AQI 37 · 93.2% Good-day share
Bradford County, Pennsylvania
Median AQI 37 · 81.6% Good-day share
Brown County, Wisconsin
Median AQI 37 · 73.2% Good-day share
Cass County, North Dakota
Median AQI 37 · 76.2% Good-day share
Same primary pollutant: PM2.5
PM2.5 led the AQI on the most monitored days here. These peers share that driver and the closest Good-day share (a second relationship type beyond median-AQI neighbors).
Charles County, Virginia
88.7% Good-day share · median AQI 35
Bannock County, Idaho
88.8% Good-day share · median AQI 36
Roane County, Tennessee
88.6% Good-day share · median AQI 29
Carter County, Kentucky
89.0% Good-day share · median AQI 36
Susquehanna County, Pennsylvania
88.4% Good-day share · median AQI 22
Sheridan County, Wyoming
89.1% Good-day share · median AQI 27
Florida counties on the map
Geographic containment only, other monitored counties in Florida, independent of AQI or pollutant match.
What Alachua County's air means for you
The air here stays in the breathable range year-round, with PM2.5 the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 37 means for exposure. Health guidance
- See how Alachua County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Alachua County with its Florida neighbours before drawing a conclusion about the region. All of Florida
Based on 364 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
Keep exploring the annual AQI record
Air-quality reading list
Frequently Asked Questions
What is the air quality in Alachua County, Florida? ▼
Alachua County has a median Air Quality Index (AQI) of 37, rated "Good." 88.7% of monitored days (323 out of 364) had good air quality in 2025.
What is the main pollutant in Alachua County? ▼
The primary pollutant in Alachua County is Fine Particles (PM2.5), which was the main AQI driver on 191 days (52% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Alachua County have? ▼
In 2025, Alachua County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 69.
Is the air quality in Alachua County getting better or worse? ▼
Air quality in Alachua County is improving across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2025 at 88.7% (323 of 364 days). Lowest qualifying Good-day share: 2023 at 74.0% (270 of 365 days).
What does AQI 37 mean for health? ▼
Alachua County's median AQI of 37 falls in the "Good" category. See the AQI category guide for what each range means for health.
How does Alachua County compare to other counties in Florida? ▼
Alachua County has 88.7% good air days. Nearby counties in Florida: Baker (69.5% good), Bay (66.4% good), Brevard (91.2% good), Broward (73.4% good), Citrus (71.1% good), Collier (72.0% good).
What is the 90th percentile AQI in Alachua County? ▼
The 90th percentile AQI for Alachua County is 51, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 69 (Moderate).
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.
Informational only, not professional advice. Data from EPA AQS. See our disclaimer. Spotted a figure that looks wrong? Report a correction.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Alachua County, Florida · 2020–2025
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Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.