The allergy season calendar shows when tree, grass, weed, and mold allergens peak across different US regions. Select your region to see month-by-month pollen activity and identify your worst allergy months.
Allergy Calendar
| Allergen | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|
How to Use the Allergy Season Calendar
The allergy season calendar helps you anticipate when your allergens will be highest and plan treatment proactively. Allergists recommend starting antihistamines and nasal sprays 1–2 weeks before your peak season begins, not after symptoms start.
Using the Calendar
Select your region to see when each allergen type peaks. Red cells indicate high pollen levels when symptoms will be most severe. Amber cells indicate moderate levels. If you react to multiple allergens (e.g., trees AND grass), look for periods where multiple rows show high levels simultaneously — these are your worst weeks.
Checking Daily Pollen Counts
The calendar shows seasonal patterns — not day-to-day variation. Rain temporarily reduces airborne pollen, while warm windy mornings spike counts. Check pollen.com, Weather.com, or the National Allergy Bureau for current counts in your specific city. Many weather apps now include pollen forecasts.
Frequently Asked Questions
When is allergy season?
Allergy season varies by location and allergen type. Tree pollen starts in late winter/early spring (Feb–May). Grass pollen peaks in late spring/summer (May–July). Weed pollen (especially ragweed) dominates late summer/fall (Aug–Oct). Mold spores are highest after rains and in fall during leaf decomposition.
Which region has the worst allergy season?
The Southeast US (especially Atlanta, Charlotte, Nashville) is often cited as having the worst allergy seasons, with warm temperatures extending pollen seasons longer. Texas, Oklahoma, and the South Central region are particularly bad for mountain cedar (Juniperus ashei) allergies in January–February.
How long does tree pollen season last?
Tree pollen season typically lasts 6–10 weeks. In the Southeast, it may start in February. In the Northern US and Canada, it begins in April–May. Individual tree species have their own peaks — oak, birch, maple, and cedar are common culprits. Multiple species overlapping creates prolonged high-pollen periods.
Does climate change affect allergy season?
Yes, significantly. Research shows pollen seasons have lengthened by 20+ days since 1990 in North America, and pollen concentrations have increased. Warmer springs cause earlier tree pollen release; more CO2 stimulates greater pollen production per plant. Allergists report seeing more patients and more severe symptoms over time.
How can I reduce allergy exposure?
Check daily pollen counts (pollen.com, weather apps). Keep windows closed on high-count days. Shower after outdoor activities to remove pollen from hair/skin. Wear sunglasses outdoors. Start antihistamines 1–2 weeks before your peak season begins. Nasal corticosteroid sprays are most effective when used consistently throughout the season.