Quick Answer
Your geographic location determines which allergens affect you, when your season peaks, and how severe your reactions will be. Southern states have longer and more intense allergy seasons. The South-Central US (especially Texas and Oklahoma) is particularly challenging due to year-round triggers including cedar fever in winter, oak in spring, grass in summer, and ragweed in fall.
Key Takeaways
- Your region's dominant plant species, climate, and wind patterns determine your specific allergy triggers and season length
- Texas and the South-Central US have year-round allergy seasons from cedar (winter), tree pollen (spring), grass (summer), and ragweed (fall)
- The AAFA's Allergy Capitals report ranks cities annually — Wichita, Virginia Beach, Dallas consistently rank worst
- Climate change has extended pollen seasons by ~20 days across North America since 1990, with northern states most affected
- Relocating to avoid allergens rarely provides permanent relief — local sensitization typically occurs within 2–5 years
- Allergen immunotherapy tailored to your regional allergen profile provides definitive long-term relief regardless of location
Geography and Seasonal Allergy Botany
Pollen counts and seasons vary dramatically by geographic region. The "allergy capitals" often feature dense populations of highly allergenic trees combined with weather patterns that trap pollen close to the ground and extended warm seasons. Understanding your region's dominant allergens is essential for effective seasonal allergy management.
| US Region | Primary Season | Dominant Allergens | Severity |
|---|---|---|---|
| Northeast US | Spring + Late Summer | Birch, oak, timothy grass, ragweed | Moderate–High |
| Southeast US | Year-round | Oak, Bermuda grass, ragweed, mold | Very High |
| South-Central (TX, OK) | Year-round (worst Nov–Mar) | Mountain cedar, oak, ragweed | Extreme |
| Midwest US | Spring + Fall | Tree pollen, ragweed, mold | High |
| Pacific Northwest | Spring | Alder, birch, mold (year-round) | Moderate |
| Southwest US | Winter–Spring | Mountain cedar, mulberry, desert weeds | Moderate–High |
The Impact of Climate Change on Regional Seasons
Climate change is rapidly reshaping regional allergy patterns. Our climate change and allergies guide details how rising temperatures are extending seasons and increasing pollen potency across all US regions — with northern states experiencing the most dramatic changes as previously mild seasons intensify.