Caribou, Maine Air Quality
Caribou has a median AQI of 36, earning an air quality grade of A — excellent air quality that ranks better than 79% of US cities. Air quality has remained relatively stable over the past decade. Ground-level ozone is the primary concern, typically peaking on warm sunny days due to vehicle and industrial emissions. In 2025, Caribou recorded 153 good air quality days (84% of monitored days) and 2 unhealthy days.
Population: 7,382 • County: Aroostook
Current AQI
Quick Facts
| Current AQI | 38 — Good |
| Air Quality Grade | A |
| Median AQI (2025) | 36 |
| vs. U.S. Cities | Better than 79% |
| Primary Pollutant | Ozone |
| Unhealthy Days/Year | 2 |
| 10-Year Trend | → Stable |
| Data Source | EPA AQS (historical) · AirNow (live) |
Health Recommendation
Air quality is satisfactory, and air pollution poses little or no risk.
It's a great day to be active outside!
5-Day AQI Forecast
Last 90 Days
Current Pollutant Levels
Real-time data from EPA AirNow
Local Air Quality Context
Air quality data for Caribou is sourced from the Presque Isle Regional Office monitoring area, located approximately 12 miles from city center. This EPA-certified station continuously tracks ground-level ozone, the primary driver of air quality alerts in this area.
Caribou has relatively consistent air quality throughout the year without a strong seasonal peak. Air quality is primarily influenced by local traffic, industrial activity, and regional weather patterns rather than a single seasonal driver.
AQI Trend (10 Years)
Air Quality Days by Year
Caribou Median AQI by Year
Annual EPA air quality data for Caribou — median AQI, day-category breakdown, and primary pollutant per year.
| Year | Median AQI | Good Days | Unhealthy Days | Max AQI | Primary Pollutant |
|---|---|---|---|---|---|
| 2025 | 36 | 153 | 2 | 131 | Ozone |
| 2024 | 35 | 299 | — | 96 | PM2.5 |
| 2023 | 37 | 277 | 3 | 142 | PM2.5 |
| 2022 | 34 | 304 | — | 80 | PM2.5 |
| 2021 | 35 | 305 | 2 | 182 | Ozone |
| 2020 | 36 | 316 | 1 | 205 | Ozone |
| 2019 | 36 | 304 | 2 | 182 | PM2.5 |
| 2018 | 42 | 262 | 2 | 216 | PM2.5 |
| 2017 | 40 | 257 | 1 | 120 | PM2.5 |
| 2016 | 39 | 265 | 1 | 169 | PM2.5 |
Source: EPA Air Quality System (AQS) annual summaries. "Unhealthy Days" includes Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy, and Hazardous categories.
2025 Air Quality Summary
Primary Pollutant Days (2025)
Days when each pollutant was the primary driver of AQI. Learn about pollutants →
Frequently Asked Questions About Caribou Air Quality
What is the air quality in Caribou today?
The current AQI in Caribou is 38, rated "Good". Air quality is good — outdoor activity is safe for everyone today. Air quality is satisfactory, and air pollution poses little or no risk.
Is air quality in Caribou getting better or worse?
Air quality in Caribou has been stable. The median AQI has dropped 3 points (from 39 in 2016 to 36 in 2025).
What is the most common air pollutant in Caribou?
Ozone is the primary air pollutant in Caribou, responsible for 100 days (55% of monitored days) in 2025. Ground-level ozone forms when sunlight reacts with emissions from vehicles and industry, typically peaking on hot summer afternoons.
How many unhealthy air days does Caribou have per year?
In 2025, Caribou recorded 84% good air quality days (153 days) out of 182 monitored days. There were 2 Unhealthy for Sensitive Groups days and 0 Unhealthy days (AQI above 100). The highest single-day AQI recorded was 131.
What air quality grade does Caribou receive?
Caribou receives an air quality grade of A, placing it better than 79% of US cities. This is based on a median AQI of 36 in 2025, with 153 good air quality days. The EPA monitors air quality in this area continuously using certified monitoring stations.
Air Quality Grade
Better than 79% of US cities
Nearby Cities
Get AQI Alerts
Receive notifications when air quality changes in Caribou
National Rankings
See how Caribou compares to every other US city by air quality.
Best Air Quality Cities →All city rankingsRecommended Air Purifiers for Caribou
Ozone is Caribou's primary pollutant. Standard HEPA filters don't capture ozone molecules — you need activated carbon or PECO technology to chemically break them down. We highlight those units here.
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Molekule Air Pro
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Honeywell HPA300
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