Is it allergy season in Maryland?

Maryland's geography creates a tale of two allergy experiences: the humid Chesapeake lowlands around Baltimore and the Eastern Shore, where moisture amplifies pollen concentration, and the drier mountain regions to the west near Hagerstown, where elevation compresses and intensifies the season. Baltimore and the DC suburbs consistently experience heavy oak in spring, followed by grass season and a pronounced ragweed stretch in late summer.

Maryland spans a remarkable geographic range — from the flat, humid Eastern Shore to the Piedmont Plateau to the Appalachian Mountains in the west. Each region experiences different allergen timing and intensity, with the DC suburb corridor often experiencing the state's most acute spring pollen season.

Baltimore Metro

Chesapeake humidity amplifies every season

Baltimore sits at the head of the Chesapeake Bay, where humidity keeps pollen airborne longer and at higher concentrations. Heavy oak season in April–May, followed by significant grass pollen through June and July, then ragweed through September.

Trees · Apr–MayGrass · Jun–JulRagweed · Aug–Sep

DC Suburbs / Piedmont

Urban heat island advances the season

Rockville, Gaithersburg, and the DC corridor experience an urban heat island effect that can push tree pollen 1–2 weeks ahead of rural Maryland. Oak and maple are especially heavy. The Potomac River valley also traps pollen on still days.

Trees early · Mar–MayGrass · May–JulRiver valley trapping

Eastern Shore

Flat, humid coastal plain

The Eastern Shore's flat terrain and maritime humidity create a prolonged allergy season. Sea breezes can disperse pollen during the day but dying winds in the evening allow ground-level concentrations to build. Grass pollen from local agriculture is particularly notable.

Trees · Apr–MayGrass · Jun–Jul (coastal)Ragweed · Aug–Sep

Western MD Mountains

Elevation compresses the season

The Appalachian ridges near Hagerstown and Cumberland see a later, more compressed allergy season. Tree pollen can lag 2–3 weeks behind Baltimore. However, the compressed timeline means peak counts arrive quickly. Grass pollen is somewhat lighter than the lowlands.

Trees delayed · MayShorter season overallGrass · Jun–Jul

Each row shows a full year of pollen for one region — trees in blue, grasses in green, weeds in amber. Look for where all three rows go quiet at the same time — that's your window.

Oral Allergy Syndrome (also called pollen-food allergy syndrome) causes tingling or mild itching in the mouth when you eat certain raw foods during the relevant pollen season. The proteins in the food are similar enough to the pollen protein that your immune system cross-reacts. Cooking usually deactivates the offending protein, so the same food cooked may cause no reaction.

Oak & Birch pollen

Stone fruits & apples

Apples, peaches, cherries, plums, pears, almonds, hazelnuts, carrots, celery

Peak risk April–May in Maryland. The DC and Baltimore area oak season is among the Mid-Atlantic's heaviest. Peeling fruit removes most of the cross-reactive protein.

Grass pollen

Tomatoes, potatoes & melons

Tomatoes, potatoes, kiwi, watermelon, cantaloupe, oranges (in some cases)

Peak risk May–July. The Eastern Shore's agricultural areas amplify grass pollen. Chesapeake humidity keeps pollen airborne longer than in drier inland regions.

Ragweed

Melons & bananas

Watermelon, cantaloupe, honeydew, banana, zucchini, cucumber, sunflower seeds

Peak risk August–September. Baltimore and the DC suburbs are among the Mid-Atlantic's most ragweed-affected metros.

Not medical advice. If you suspect OAS, speak with an allergist — it can sometimes progress, and symptoms that extend beyond the mouth should be evaluated.