Walking Activity AQI Thresholds
AQI 0-50: Perfect for All Walking
Safe for leisurely strolls, brisk walks, and long-distance walking.
AQI 51-100: Good for Most Walkers
Normal walking safe. Sensitive individuals may slow pace slightly on brisk walks.
AQI 101-150: Slow Pace, Shorter Duration
Reduce pace to leisurely stroll. Limit to 30-45 minutes. Take breaks. Sensitive groups use caution.
AQI 151-200: Brief Walks Only
Essential errands only, very slow pace, 15 minutes max. Wear N95 mask. Most should avoid.
AQI 201+: Do Not Walk Outdoors
Stay indoors. Use treadmill or indoor walking instead.
Exertion Level by Walking Type
Leisurely Walking (Casual Pace)
- Pace: 2-2.5 mph, conversational
- Safe up to: AQI 150 for most people
- AQI 151-200: Brief walks only (15 minutes)
- Breathing rate: 1.5-2x resting
Moderate Walking (Steady Pace)
- Pace: 3-3.5 mph, can still talk but breathing harder
- Safe up to: AQI 100
- AQI 101-150: Reduce to leisurely pace
- Breathing rate: 2-3x resting
Brisk Walking (Fitness Walking)
- Pace: 4+ mph, vigorous effort
- Safe up to: AQI 75
- AQI 76-100: Reduce to moderate pace
- AQI 101+: Switch to leisurely walk or indoor treadmill
- Breathing rate: 3-4x resting
Power Walking / Race Walking
- Pace: 4.5+ mph, athletic intensity
- Safe up to: AQI 70
- AQI 71-100: Reduce intensity significantly
- AQI 101+: Move to indoor treadmill
- Breathing rate: 4-5x resting
Route Selection for Better Air Quality
Best Walking Routes
- Parks and greenways: Trees filter air, fewer vehicles
- Waterfront paths: Better air circulation, ocean/lake breezes
- Residential streets: 40-60% less pollution than main roads
- Trails through forests: Natural air filtration
- College campuses: Large green spaces, limited traffic
Routes to Avoid
- Major roads and highways: 3-5x higher pollution
- Bus routes: Diesel exhaust concentration
- Industrial areas: Multiple pollution sources
- Parking structures: Concentrated vehicle emissions
- Drive-through lines: Idling vehicle fumes
Best Times for Walking
Early Morning (6 AM - 9 AM)
Optimal choice: Lowest AQI, cooler temperatures, peaceful. Best for fitness walks and longer distances. Ozone hasn't formed, traffic minimal.
Late Morning (9 AM - 11 AM)
Still good: AQI starting to rise but acceptable. Good for moderate walks. Check current levels if planning brisk pace.
Midday (11 AM - 3 PM)
Least ideal: Peak ozone formation. AQI typically 20-40 points higher. Walk only if morning AQI was below 40, and keep pace leisurely.
Late Afternoon (4 PM - 6 PM)
Avoid if possible: Still elevated ozone, plus rush hour traffic pollution. Wait until after 6:30 PM if you can.
Evening (6:30 PM - Dark)
Second best: Ozone dissipating, cooling temperatures. Good alternative to morning. Ensure adequate lighting for safety.
Alternative Indoor Walking
Indoor Options
- Treadmill: Best for maintaining fitness routine
- Indoor track: Available at gyms and rec centers
- Mall walking: Climate controlled, popular senior activity
- Indoor shopping centers: Walk while window shopping
- Museum walking: Cultural experience plus exercise
- Airport terminals: Large spaces if you have access
Best Cities for Walking
Excellent Year-Round (AQI Below 35)
- Seattle, WA - Walkable neighborhoods, clean air
- Portland, OR - Pedestrian-friendly, Pacific air
- San Diego, CA - Coastal climate, good air quality
- Honolulu, HI - Ocean breezes, consistent clean air
- Burlington, VT - Small city, mountain air
Good Most of Year (AQI 35-50)
- Minneapolis, MN - Good air, many walking paths
- Boston, MA - Walkable city, generally clean air
- San Francisco, CA - Hilly but good air quality
- Raleigh, NC - Southern charm, decent air
Safety Checklist for Walkers
Before Your Walk
- ✓Check current AQI and hourly forecast
- ✓Choose route away from busy roads if AQI is 51-100
- ✓Plan indoor backup if air quality may deteriorate
- ✓Bring phone to check AQI during long walks
- ✓Wear N95 mask if walking in AQI 101-150
During Your Walk
- ✓Monitor breathing - difficulty is warning sign
- ✓Watch for coughing, eye irritation, throat scratchiness
- ✓Slow pace immediately if symptoms develop
- ✓Turn around early if air quality seems worse
- ✓Stay hydrated, especially when masked
Special Considerations
Walking for Seniors
- More susceptible to air pollution effects
- Avoid walking when AQI exceeds 100
- Choose flat, easy routes on moderate air quality days
- Walk with companion for safety
- Consider indoor mall walking as safer alternative
Walking with Strollers
- Babies more vulnerable - keep at AQI below 100
- Stroller height puts child closer to ground-level pollution
- Avoid walking along busy roads even when AQI is good
- Choose park paths away from traffic
- Morning walks better for infant exposure
Dog Walking
- Dogs also affected by air pollution
- Shorten walks when AQI is 101-150
- Avoid pavement in hot weather with poor air quality (double stress)
- Choose grassy parks over sidewalks along roads
- Watch for excessive panting or reluctance to walk
Walkers with Respiratory Conditions
- Walk only when AQI is below 100
- Always carry rescue inhaler
- Use preventive medication before walk when AQI is 51-100
- Keep pace leisurely on moderate air quality days
- Have plan to cut walk short if symptoms develop