Diving Into the U.S. Spring Allergies Forecast

Posted: March 17, 2023 10:24 am

Despite last week’s nor’easter and plenty of snow still hanging around much of the country, spring is definitely on the way. Along with the warmer temperatures and beautiful flowers in bloom, the season also brings the onset of seasonal allergies for millions of Americans. What does the spring allergy season have in store this year? Read on for all of the details.

How Forecasters Determine Allergies Severity Predictions

While it is not entirely predictive, forecasters and climatologists are able to look at a variety of data and weather patterns to make educated guesses about the severity of the upcoming allergy season. A new report out of the nonprofit group Climate Central details that the increase in the length of the growing season is translating to longer allergy seasons.

According to the latest report from the U.S.A. National Phenology Network (USA – NPN), a large portion of the Southeast, lower Midwest, and mid-Atlantic are seeing the earliest onset to spring on record. This contrasts to parts of the Southwest where winter is still lingering.

The progression of spring allergies generally starts with tree pollen in the early weeks of spring, followed by grass pollen in the late spring and early summer, and weed pollen making an appearance in the late summer and early fall.

The severity and progression of these allergens are also influenced by the weather to a great degree. For instance, pollen circulates more easily on warm and windy days. Rainy days tend to suppress the movement of pollen. By looking at the long-range forecasts for specific regions, experts can formulate predictions about allergen severity.

Tree Pollen Forecast

Tree pollen is already in full swing throughout much of the Gulf Coast and the Southeast because of February’s unseasonably warm temperatures. Even though much of this region has seen rain over the last few weeks, it has not been sufficient enough to clear out all of the pollen. This is creating high pollen counts much earlier than usual in this corner of the country.

The Northeast can also expect an earlier launch of tree pollen this year. However, cooler temperatures in the long-range forecast may keep some of these tree pollens suppressed.

Cooler than average temperature and greater amounts of rainfall will likely mean a less severe tree pollen season in the northern Plains. This will not be the case for those in the Pacific Northwest where tree pollen is expected to climb in the coming weeks. These counts are forecast to be the worst by the end of April.

For the rest of the West, the Rockies can expect a normal season while those in the Southwest are forecast to see lower tree pollen counts.

Grass Pollen Forecast

The eastern third of the U.S. is going to be under the gun for a worse than average grass pollen season. The hot zone for grass pollen is forecast to be centered on Ohio, Tennessee, and into Virginia. Warmer than normal temperatures forecast for late in the spring and early summer will contribute to these soaring levels.

Grass pollen will peak along the Gulf Coast by early May with the mid-Atlantic and Ohio Valley seeing the highest numbers just in time for the Memorial Day holiday weekend. The levels will not reach peak values until the middle of June for most of the Midwest.

The Northeast will likely be spared the worst of the grass pollen levels because of cooler temperatures and higher amounts of moisture. This will also be the case in the northern Plains, the Rockies, and the Four corners regions. Grass allergies sufferers will rejoice in the slow start to the warmer weather, helping to keep these allergens suppressed.

As far as peak season for this allergen, you can expect the grass pollen to reach its worst levels by the middle of May in Arizona, New Mexico, and the western portions of Texas. The Rockies and the northern Plains will not see this peak until the beginning of June.

One of the silver lining of the drought conditions out West over the last few years is that the dryness has kept grass pollen at bay. However, the recent surge of moisture over California will translate to levels that are predicted to climb back into normal range this year.

The Pacific Northwest will be dealing with higher levels of grass pollen in addition to the elevated tree pollen levels. Warmer than average temperatures heading into the summer and the moisture from the spring will contribute to higher counts of this pollen. Residents in places such as Seattle and Portland will want to be prepared for this onslaught with the right coping strategies and medicines.

Weed Pollen Forecast

Although the East Coast will get off fairly easy for tree pollen and grass pollen, it will be weed pollen triggering allergies in the late summer and early fall time period. An increase in temperature readings and moisture levels will field the growth of these weeds.

Weed pollen levels are forecast to surge in late July and early August through the Southeast and the Gulf Coast. The mid-Atlantic and Ohio Valley will see the highest levels beginning in mid August and continuing into early September. The peak of weed pollen will hold off until well into September for the Northeast.

A lack of precipitation across the northern Plains will keep weed pollen levels lower than usual. Meanwhile, these levels will hover around average in the southern Plains.

The Southwest and the southern Rockies will be happy to learn that drier conditions will mitigate the increase in weed pollen counts. However, the northern Rockies are bracing for weed pollen levels to land higher than average. This includes the states of Colorado, Idaho, and Montana. The peak for this region will fall in the late summer and into the early fall. The rest of the West Coast should see weed pollen levels in the normal range.

Over 50 million Americans suffer from seasonal allergies. Knowing if your area will experience higher than normal levels of these common allergens this spring will help you to prepare accordingly.

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