Allergy season in the U.S. was expected to be longer and more intense in 2026, with high pollen levels forecast in 29 states.
Tree pollen has already started early in parts of the south and west, including Arizona, because of warmer winter and spring temperatures.
As spring warmth spreads north, pollen levels will rise rapidly across the country. Grass pollen will spike in the Great Lakes and northern Plains during early summer, while weed pollen was expected to be strongest in the Rocky Mountains later in summer and fall.
Weather patterns such as temperature swings, rainfall, wind and late frosts will cause sharp fluctuations in pollen levels. Scientists also say climate change is making allergy seasons longer and more severe, because warmer temperatures and longer growing seasons allow plants to release pollen for extended periods.
Here’s what to know and what to expect during allergy season in Arizona.
Is it currently allergy season in Arizona?
Yes, allergy season has already started in Arizona, especially in southern parts of the state. Tree pollen typically begins appearing as early as late January or February, and it increases through the spring.
Spring is a peak time, with high pollen counts from trees like olive, mulberry and ash starting in February and lasting through April. Mesquite, pine, and palo verde also contribute to high pollen levels through May.
What are the worst months for allergies in Arizona?
The worst months usually occur during spring and fall:
- February–April: Tree pollen (juniper, ash, mesquite, olive).
- May–June: Grass pollen peaks.
- September–October: Weed pollen such as ragweed.
For many people in Phoenix, March through May tends to be the most intense period of allergy symptoms.
Why are allergies so bad in AZ right now?
Several factors make allergies worse in Phoenix and other Arizona cities such as early tree pollen due to warm winter and spring temperatures. The dry desert air also allows pollen and dust to stay airborne longer.
Windy conditions that spread pollen across large areas could be another factor or even urban landscaping with highly allergenic plants like olive and mulberry trees. Not to mention climate change, which lengthens growing seasons and increases pollen production. Because of these factors, Arizona often has nearly year-round pollen activity.
What are the five worst states for allergies?
According to an AccuWeather 2026 US Allergy Forecast, based on allergy rankings and pollen levels, some of the worst states for allergies commonly include:
- Texas.
- Louisiana.
- Oklahoma.
- Georgia.
- Tennessee.
These areas frequently have high pollen counts, long growing seasons and warm, humid climates that encourage plant growth.
How to beat seasonal allergies?
Some effective strategies from the Mayo Clinic include:
- Check daily pollen forecasts before going outside.
- Keep windows closed during high pollen days.
- Shower and change clothes after being outdoors.
- Use antihistamines or nasal sprays if recommended.
- Avoid outdoor activity during peak pollen hours (morning).
For severe allergies, doctors may recommend immunotherapy.
How to get rid of allergies in Arizona?
Because desert allergens behave differently, these tips help locally:
- Run air conditioning instead of opening windows.
- Clean dust frequently and vacuum with HEPA filters.
- Avoid yard work when pollen counts are high.
- Wear sunglasses or a mask during windy days.
- Rinse sinuses with saline to remove pollen.
Do air purifiers help with allergies?
Yes, air purifiers with HEPA filters can significantly reduce indoor allergens by trapping pollen and dust in the air. They work best when placed in frequently used rooms like bedrooms and when combined with regular cleaning and closed windows during high-pollen periods.
Reporting by Tiffany Acosta, Arizona Republic
