Late summer and fall allergy season

By the time August rolls around, many are preparing to head back to school—and maybe even hoping for a break from the summer heat. But make no mistake: August is still very much in the heart of summer.

Here in the Midwest, it’s known for three things: heat, humidity and the start of secondary allergy season, especially for hay and ragweed.

Ragweed season kicks off in August as the plant enters its natural bloom cycle. Stretches of hot, sunny and increasingly dry weather this time of year create ideal conditions for ragweed pollen release.

As the second week of August comes to a close, levels of ragweed pollen have yet to spike across Northwest Missouri and Northeast Kansas. The next two weeks will be a turning point for the presence of ragweed pollen, as blooms mature.

Speaking of flowering late summer weeds, the well-known goldenrod has already begun to appear. Often blamed as a primary source of allergens this time of year, goldenrod’s showy yellow flowers produce clumps of sticky pollen that don’t easily go airborne.

By contrast, ragweed pollen is fine and powdery, allowing its grains to easily spread through the open air.

The timing and severity of fall allergies often depend on broader weather patterns. If warmer temperatures linger into September and October, ragweed plants may continue releasing pollen longer than usual—extending allergy season into the fall.

In fact, fall allergies typically linger in some capacity until the season’s first frost finally arrives.