The pollen count is a measure of how much pollen is in the air in a certain area at a specific time. It is expressed in grains of pollen per square meter of air collected over 24 hours. Pollen counts tend to be highest early in the morning on warm, breezy days and lowest during chilly, wet periods.

One of the most common triggers for seasonal allergies are pollen spores. They are small, light and dry, so the wind can carry them. Pollen counts can vary day-to-day, depending on several factors, including the weather. For example, dry, windy weather spreads pollen quickly. However, heavy rains and humid weather conditions weigh down pollen, keeping it on the ground. In general, plants and trees that pollinate via wind cause the most problems for people with seasonal allergies.

Weed Pollens: Ragweed is a potent and widespread cause of pollen allergy symptoms. This tall, branched plant is found throughout the lower 48 states in dry fields and pastures, by roadsides, and at construction sites.

Grass Pollens: Of more than 1,200 species of grass, the main culprits of allergies are Timothy, Johnson, Bermuda, blue, orchard, and sweet vernal grasses. Grasses generally release pollen from late spring until fall.

Tree Pollens: When it comes to trees, watch out for hardwood deciduous trees—birch, oak, elm, maple, ash, alder, and hazel. These trees generally pollinate from late winter to the end of spring, depending on your geographic location.

Some common symptoms of a pollen allergy may include sneezing, itchy watery eyes, runny nose, and nasal congestion. Allergy testing by an allergist can verify whether you’re reacting to pollen or have an allergy to another substance, such as mold, dust mites, or pet dander.

• Consider taking allergy medication before symptoms start, especially if high pollen counts are predicted.
• Keep windows closed, especially during high pollen periods.
• Avoid outdoor activities during peak pollen times (early morning).
• Shower and change clothes after being outside to remove pollen.

Seasonal allergies describe allergies that change with the seasons due to pollen from plants. These allergens can be difficult to manage because it seems like they’re everywhere and they’re difficult to avoid. For people with seasonal allergies, symptoms come and go with the pollination seasons of certain trees, grasses or weeds. Pollen levels from these plants can vary day to day, depending upon several factors, including the weather. High pollen levels can, in turn, affect the severity of symptoms.