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Spring Air Quality Patterns

Spring brings improving air quality as temperatures rise and winter inversions break up, but pollen season can affect respiratory health. March through May shows distinct regional patterns.

Good

Overall Season Rating

March-May

Peak Months

Pollen

Primary Concern

45-65

Typical AQI Range

Month-by-Month Patterns

MAR

March: Transition Month

Typical AQI: 50-70

Winter inversions begin breaking up. Early tree pollen starts in southern regions. Occasional dust storms in Southwest.

Best Cities

Seattle, Portland, San Francisco - Post-winter cleanup, before summer dry season. Great Lakes cities improving rapidly.

Early PollenImprovingVariable Wind

APR

April: Peak Spring

Typical AQI: 40-60

Best air quality month in many regions. Tree pollen peaks nationwide. Low ozone levels before summer heat. Excellent outdoor conditions.

Regional Highlights

Northeast and Midwest excellent. Southwest dust season. Pacific Northwest ideal. Southeast manages pollen well.

Best OverallHigh PollenLow Ozone

MAY

May: Late Spring Warmup

Typical AQI: 45-70

Grass pollen replaces tree pollen. First ozone alerts possible in hot regions. Still generally good air quality before peak summer.

Watch Areas

Southern California begins ozone season. Texas heat drives early pollution. Mountain West excellent. Florida humidity increases.

Still GoodGrass PollenEarly Ozone

Regional Spring Patterns

Pacific Northwest

Best Months: April-May

Typical AQI: 35-55 (Excellent)

Key Features: Rain cleans air, cool temps prevent ozone, minimal pollen compared to other regions

Southwest

Best Months: March-April

Typical AQI: 50-80 (Good to Moderate)

Key Features: Dust storms common, early heat in May, low humidity advantages

Northeast

Best Months: April-May

Typical AQI: 40-60 (Good)

Key Features: Consistent quality, heavy tree pollen, coastal areas best

Southeast

Best Months: March-April

Typical AQI: 45-70 (Good)

Key Features: Early warmth, pine pollen heavy, humidity increases in May

Primary Spring Pollutants

1. Pollen (Non-AQI)

While not measured in AQI, pollen significantly affects air quality perception and health, especially for allergy sufferers. Tree pollen peaks in spring.

Peak: April-May nationwide

2. PM2.5 Particles

Residual winter wood smoke and vehicle emissions. Generally improving through spring as heating needs decrease.

Impact: Declining March-May

3. Dust (PM10)

Southwest wind events kick up dust. Agricultural activities increase particulate matter in farming regions.

Peak: March-April in arid regions

Spring Activity Guide

Recommended Activities

Outdoor Exercise
Running, cycling, hiking - excellent conditions in April-May
Open Windows
Fresh air ventilation ideal during late spring mornings
Outdoor Events
Festivals, sports events, picnics - great air quality window

Precautions Needed

Pollen Allergies
Take antihistamines before outdoor activities, especially mid-morning
Dust Storms
Southwest regions: check forecasts, avoid outdoor activity during events
May Heat
Southern regions: watch for first ozone alerts as temperatures rise