Reading AQI Forecasts: How to Plan Your Week Ahead

Most people check air quality reactively—they look outside, see haze, check their app, and then cancel their run. By then, it's too late to reschedule.

The smarter approach: Check the AQI forecast at the start of your week, identify good and bad air days, and plan proactively around air quality patterns.

Just as you wouldn't schedule an outdoor wedding without checking the weather forecast, you shouldn't plan exercise, outdoor events, or activities with children without checking the AQI forecast.

Let's learn how to read and use AQI forecasts effectively.

Where to Find AQI Forecasts

AirNow.gov (United States)

Best official source for U.S. forecasts

What you get:

• Today and tomorrow forecasts for all U.S. locations
• Pollutant-specific forecasts (ozone, PM2.5)
• Regional maps showing forecast AQI
• Discussion explaining why forecasters expect certain conditions

How to access:

1. Visit airnow.gov
2. Enter your zip code or city
3. Click "Air Quality Forecast"

Strengths: Authoritative, detailed explanations Limitations: Only 1-2 days ahead, U.S. only

IQAir AirVisual

Best for extended forecasts

What you get:

• 7-day AQI forecast
• Hourly breakdown for next 24-48 hours
• Global coverage
• Multiple pollutants

How to access:

• IQAir app or website (iqair.com)
• Select your city
• View forecast tab

Strengths: Week-ahead planning, international Limitations: Forecasts less accurate beyond 2-3 days

BreezoMeter

Best for hour-by-hour detail

What you get:

• Hourly forecasts for 24-96 hours
• Street-level resolution
• Integrated with weather apps

Strengths: Very granular timing Limitations: May not be available in all locations

Weather Apps

Many weather apps now include AQI forecasts:

• Apple Weather: Basic AQI included
• The Weather Channel: AQI forecast alongside temperature
• AccuWeather: AQI in extended forecast

Convenience: One-stop weather + air quality planning

Understanding Forecast Components

AQI Categories

Forecasts typically predict which AQI category each day will fall into:

• Good (0-50): Green - unrestricted outdoor activity
• Moderate (51-100): Yellow - generally acceptable
• Unhealthy for Sensitive Groups (101-150): Orange - caution for vulnerable people
• Unhealthy (151-200): Red - everyone should limit outdoor time
• Very Unhealthy (201-300): Purple - avoid outdoor exertion
• Hazardous (301+): Maroon - stay indoors

How to read: Forecasts might say "Orange (USG)" or "AQI 100-150" or show color-coded boxes.

Pollutant Forecasts

Important: Forecasts often specify which pollutant will drive AQI.

Common patterns:

• Summer days: "Ozone expected to reach Orange category"
• Winter inversions: "PM2.5 forecast to reach Red category"
• Wildfire events: "PM2.5 from smoke could reach Purple category"

Why this matters: Different pollutants require different protective strategies (see our pollutants comparison guide).

Forecast Confidence

Some forecasts indicate confidence level:

• High confidence: Meteorological conditions are clear
• Moderate confidence: Some uncertainty in weather or emission patterns
• Low confidence: Unpredictable conditions (e.g., wildfire behavior, storm tracks)

How to use: Low confidence = have backup plans ready.

Reading the Forecast Discussion

What Forecasters Tell You

AirNow.gov and some other sources include forecast discussions—these are gold mines of information.

Example discussion:

"Ozone is forecast to reach Code Orange (USG) levels Tuesday and Wednesday due to hot temperatures (95-100°F), sunny skies, and light winds. Afternoon highs expected between 3-6 PM. Thursday's approaching cold front should bring relief with increasing clouds and winds."

What this tells you:

• Why: Hot, sunny, stagnant = ozone formation
• When: Afternoon peak (3-6 PM)
• Duration: Two days (Tuesday-Wednesday)
• Relief: Thursday improvement expected

Use this to plan: Schedule outdoor exercise for early morning Tuesday/Wednesday, avoid afternoon exposure, plan outdoor errands for Thursday.

Key Phrases and What They Mean

"Stagnant air mass"

• Meaning: Light winds, pollution accumulates
• Implication: AQI likely to worsen progressively over days
• Plan: Front-load outdoor activities early in event

"Temperature inversion expected"

• Meaning: Warm air trapping cool air and pollution near ground
• Implication: Particularly bad morning air, may improve afternoon if sun breaks inversion
• Plan: Delay morning activities, reassess midday

"Smoke transport from [region]"

• Meaning: Wildfire smoke traveling from elsewhere
• Implication: May arrive/depart suddenly based on wind shifts
• Plan: Monitor real-time conditions, have indoor backup plans

"Monsoon/frontal passage will improve conditions"

• Meaning: Rain or wind shift coming
• Implication: Air quality will improve substantially
• Plan: Postpone outdoor activities until after front passes

"Photochemical smog formation likely"

• Meaning: Ozone will form from sun + pollutants
• Implication: Morning OK, afternoon bad
• Plan: Outdoor activities before 11 AM

Seasonal Forecast Patterns

Understanding seasonal patterns helps you anticipate when forecasts matter most.

Summer: Ozone Season

Pattern:

• Hot, sunny days = high ozone risk
• Overnight/early morning: Low ozone
• Afternoon (2-6 PM): Peak ozone

Forecast clues:

• Temperature >90°F + sunny = likely Orange or Red ozone
• Heat wave = multi-day ozone episode

Planning strategy:

• Exercise before 10 AM or after 8 PM
• Indoor activities during peak heat
• Weekday vs. weekend patterns (lower weekday traffic in some areas)

Winter: PM2.5 Inversions

Pattern:

• Cold, calm nights = temperature inversions
• Morning: Worst PM2.5 (trapped under inversion)
• Midday: May improve if sun breaks inversion

Forecast clues:

• "Clear skies and light winds" = inversion likely
• "Multi-day high pressure system" = prolonged poor AQI

Planning strategy:

• Delay morning exercise until 10 AM-noon
• Mornings indoors during inversion periods
• Check if forecast predicts inversion breakup

Wildfire Season: Smoke Events

Pattern:

• Extremely variable
• Depends on fire location, wind direction, atmospheric mixing
• Can change hour-by-hour

Forecast clues:

• "Smoke impacts expected" = prepare for bad air
• "Wind shift may improve/worsen conditions" = volatile situation

Planning strategy:

• Daily reassessment needed
• Create clean air room in advance
• Have N95 masks ready
• Flexibility required (cancel/postpone outdoor plans)

Planning Your Week: Practical Application

Sunday Evening Routine

Step 1: Check 7-day forecast

• Open IQAir or AirNow
• Note which days are forecast Good/Moderate vs. Unhealthy

Step 2: Identify your air quality "budget"

• Days forecast Green/Yellow: Unrestricted outdoor time
• Days forecast Orange: Limit prolonged outdoor exertion
• Days forecast Red+: Minimize or avoid outdoor activities

Step 3: Schedule accordingly

• Outdoor exercise: Schedule for Green/Yellow days
• Outdoor errands: Batch on good air days if possible
• Children's outdoor time: Prioritize good air days
• Indoor alternatives: Prepare for Red days (gym instead of outdoor run, indoor playtime for kids)

Example Week Plan

Forecast:

• Monday: AQI 40 (Good)
• Tuesday: AQI 75 (Moderate)
• Wednesday: AQI 130 (Unhealthy for Sensitive Groups - Ozone)
• Thursday: AQI 165 (Unhealthy - Ozone)
• Friday: AQI 90 (Moderate)
• Weekend: AQI 50-60 (Good-Moderate)

Your plan:

• Monday: Long outdoor run, yard work, kids play outside freely
• Tuesday: Normal outdoor activities, slightly shorter workouts
• Wednesday: Move exercise to early morning (before ozone forms), reduce intensity
• Thursday: Indoor gym day, no outdoor exercise, brief outdoor errands only
• Friday: Resume moderate outdoor activities
• Weekend: Major outdoor activities (hiking, sports)

Result: You exercised 5-6 days but minimized exposure by avoiding Thursday's worst air and timing Wednesday's activity early.

Day-of Adjustments

Forecasts aren't perfect. Check real-time AQI the morning of to confirm forecast.

When Reality Differs from Forecast

Forecast: Orange, Reality: Green

• Good news! Enjoy unrestricted outdoor time
• Weather shifted favorably (unexpected wind, earlier rain)

Forecast: Yellow, Reality: Red

• Adjust plans immediately
• Move workout indoors or postpone
• Wildfire smoke may have arrived unexpectedly

Hourly variability:

• Ozone: Check afternoon updates (often worsens)
• PM2.5: Check whether improving or worsening trend
• Smoke: Can change dramatically with wind shifts

The Morning Check-In

Before outdoor exercise:

1. Check current AQI (app or monitor)
2. Check if conditions are improving or worsening
3. Decide: Go now, delay 2-3 hours, or skip entirely

Decision tree:

• AQI <100: Proceed as planned
• AQI 100-150 + you're healthy: Moderate intensity OK, watch for symptoms
• AQI 100-150 + you're sensitive: Reduce duration/intensity or move indoors
• AQI 150+: Move indoors

Special Considerations

For Athletes and Serious Exercisers

Training around air quality:

• Schedule hard workouts on good air days
• Easy/recovery days on moderate air days
• Rest or indoor days when AQI poor
• Race scheduling: Check historical AQI data for race date/location

Example training week:

• Monday (AQI 45): Interval training
• Tuesday (AQI 60): Tempo run
• Wednesday (AQI 120): Easy run, shorter duration
• Thursday (AQI 170): Indoor cross-training or rest
• Friday (AQI 80): Moderate run
• Weekend (AQI 50): Long run

For Parents

Planning kids' outdoor time:

• Playgrounds/outdoor play: Schedule for Green/Yellow days
• Sports practice: Check forecast before committing to teams (some practice regardless of AQI—advocate for AQI policies)
• School recess: Know your district's AQI policy (many keep kids inside at Orange+)
• Birthday parties/events: Check forecast before booking outdoor venues

For Outdoor Workers

Employer communication:

• Share forecast with supervisor if concerned
• Some jurisdictions require employer protections above certain AQI thresholds
• Know your rights regarding N95 mask use

Common Forecast Mistakes to Avoid

❌ Assuming morning AQI holds all day

• Ozone peaks in afternoon
• Check hourly forecast

❌ Ignoring "for sensitive groups" warnings

• If you have asthma, are elderly, or have heart disease, this means you
• Don't dismiss orange category

❌ Planning based on yesterday's air

• AQI can change dramatically day-to-day
• Always check current forecast

❌ Trusting only one source

• Cross-reference AirNow + IQAir + real-time monitor
• Forecasts can be wrong

❌ Not having backup plans

• Indoor alternatives should always be ready
• Especially for important events (kids' birthday, etc.)

The Bottom Line

AQI forecasts are free, readily available, and can dramatically reduce your pollution exposure if used proactively.

Weekly routine:

1. Sunday: Check 7-day forecast
2. Schedule outdoor activities for good air days
3. Prepare indoor alternatives for poor air days
4. Morning of: Confirm forecast with real-time AQI

Benefits:

• Reduce annual exposure by concentrating outdoor time on clean air days
• Maintain exercise consistency with smart planning
• Protect vulnerable family members (children, elderly)
• Avoid last-minute cancellations with advance planning

Start this week: Check the forecast right now. When are the good air days? Plan your outdoor activities accordingly.

Your lungs don't get vacation days—protect them by planning ahead.

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Use our AQI to Cigarettes Calculator to understand what each forecast AQI level means for your health exposure.