Is the Air Quality Safe
for Hiking Today?
Real-time air quality for hikers and trail runners. Check wildfire smoke, PM2.5, and ozone before you head out.
Why Air Quality Matters for Hikers
Hikers spend hours at a time outdoors breathing deeply, often far from shelter. Wildfire smoke can travel hundreds of miles, making trails that look clear visually dangerous. PM2.5 from smoke, ozone, and allergens all spike seasonally — knowing the air quality before you leave the trailhead can make the difference between a great hike and a health risk.
AQI Thresholds for Hiking
Use this table to decide whether to hike based on current air quality. These recommendations are based on EPA and WHO guidelines for prolonged outdoor activity.
| AQI | Level | Hiking Recommendation |
|---|---|---|
| 0-50 | Good | Perfect conditions for any hike. Get out there! All intensities safe |
| 51-100 | Moderate | Most hikers can proceed normally. Monitor if you're sensitive to air quality |
| 101-150 | Unhealthy for Sensitive Groups | Those with asthma or heart conditions should shorten or delay hike. Reduce exertion; take frequent breaks |
| 151-200 | Unhealthy | All hikers should limit strenuous outdoor activity. Choose shorter, lower-intensity routes |
| 201-300 | Very Unhealthy | Avoid strenuous outdoor hiking. Postpone to another day |
| 301+ | Hazardous | Do not hike outdoors under any circumstances. Indoor activity only |
Wildfire Smoke: The Hiker's Biggest Threat
How Wildfire Smoke Spreads
Wildfire smoke contains PM2.5 at concentrations 10–100 times higher than normal background levels. It can travel hundreds of miles from the fire source, reaching trails that appear perfectly clear to the eye. AQI can spike from safe to hazardous within hours.
Seasonal Planning Matters
In the western United States and parts of Europe, wildfire season (June–October) can dramatically reduce safe hiking days. Pre-checking air quality — especially before overnight or multi-day trips — is essential during these months. Aeriqo's route-level analysis shows where smoke is worst along your planned trail.
Check the Air Along Your Trail
Upload a GPX from AllTrails, Strava, or Komoot — or draw the trail on the map — and see air quality for every segment before you commit to a full day out. One check is free, no account needed.
Check Your TrailHow We Get Our Data
Aeriqo uses official air quality monitoring data from government agencies and established providers. Data is refreshed hourly to give you the most current conditions.
Check Trail Air Quality Near Your City
Frequently Asked Questions
What is a safe AQI for hiking?
An AQI of 0–50 is ideal for hiking at any exertion level. At 51–100, most hikers can proceed normally. Above 100, those with respiratory or heart conditions should consider modifying or postponing. Above 150, all hikers should avoid prolonged outdoor activity.
Is it safe to hike when there's wildfire smoke nearby?
Wildfire smoke can make AQI spike rapidly. Even if skies look clear, check current AQI before heading out — smoke particles are often invisible but harmful. An AQI above 100 from wildfire smoke warrants postponing strenuous outdoor activity, especially multi-hour hikes.
Does elevation affect AQI and air quality readings?
Monitoring stations are typically at lower elevations, so readings may not perfectly reflect conditions at high altitude. Ground-level ozone can actually be higher in the mountains, driven by stronger sunlight and pollution carried in from lower areas. Wildfire smoke, however, often pools in valleys during temperature inversions.
How can I check air quality along a specific trail?
Aeriqo lets you draw or upload a GPX/TCX route — like a trail file from AllTrails or Strava — and see air quality across each segment of your planned route. This is especially useful during wildfire season when smoke can vary significantly across different parts of a trail.