Is it allergy season in Wyoming?

Wyoming is one of the lower-burden allergy states in the US, but it is far from pollen-free — and visitors who have never been exposed to sagebrush can develop significant reactions. The vast sage-steppe covering most of Wyoming's high plains and basins produces Artemisia (sagebrush) pollen from August through September in massive quantities. Grass provides a brief summer wave in June and July, largely from range grasses and some agricultural lands. Tree pollen is minimal — Wyoming lacks the eastern deciduous forest, and the most common trees (cottonwood, aspen, juniper) produce limited pollen relative to oak or birch. High elevation compresses the entire season into roughly 4 months. Cheyenne at lower elevation has the longest season; Laramie and mountain communities are even shorter.

Wyoming's allergy geography follows elevation. Cheyenne in the southeast sits at 6,000 feet — relatively low for Wyoming — and has the longest season. The Great Divide Basin and other high desert basins around Casper and Rock Springs are sagebrush-dominated. Mountain communities in the Tetons, Absarokas, and Bighorns have very compressed seasons. Gillette in the northeast is in the Powder River Basin energy corridor where disturbed reclamation land adds some weed pollen.

Cheyenne / Laramie Range

State's longest season — southeastern Wyoming

Cheyenne is Wyoming's capital and largest city, sitting at the southern edge of the Laramie Range. The season starts earliest here in spring and ends latest in fall. Sagebrush surrounds the city on the high plains; cottonwood follows the creeks. The Front Range urban influence from Colorado pushes some additional pollen north.

Cottonwood · Apr–MayGrass · Jun–JulSagebrush · Aug–Sep

Casper / Natrona County

Central Wyoming — classic sagebrush basin

Casper sits in the Platte River valley surrounded by the Wyoming Basin's sagebrush steppe. This is quintessential sagebrush-allergy territory — the dominant allergen source is immediately adjacent to the city. Grass provides a modest June–July wave. Winter winds are severe but carry no pollen.

Cottonwood · MayGrass · Jun–Jul (modest)Sagebrush · Aug–Sep (dominant)

Gillette / Powder River Basin

Coal country — disturbed land adds weed pollen

Gillette and the Powder River Basin have significant energy extraction activity. Disturbed reclamation land along mine sites and pipeline corridors grows prolific kochia, Russian thistle, and other weedy species that add to the late summer pollen load. Rabbitbrush is common in reclaimed areas.

Grass · Jun–JulSagebrush · Aug–SepKochia/rabbitbrush from reclaimed land

Jackson Hole / Mountain Valleys

High elevation — very short, compressed season

Jackson Hole, Yellowstone, and the Teton Valley communities experience Wyoming's most compressed allergy season. Above the treeline (roughly 10,000 feet), pollen is essentially absent. In the valley floor around Jackson (6,200 ft), grass appears briefly in July and sagebrush peaks in August. The season is typically over by mid-September.

Grass · Jul onlySagebrush · Aug–Sep (brief)Minimal tree pollen

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.

Sagebrush (Artemisia) pollen

Celery, carrots & spices

Celery, carrots, parsley, coriander, fennel, black pepper, sunflower seeds, honey

Peak risk August–September across Wyoming. Sagebrush (Artemisia tridentata) is the state's defining allergen and covers an estimated 50% of Wyoming's land area. People who have never visited the West may develop sagebrush sensitivity for the first time in Wyoming.

Cottonwood pollen

Stone fruits & apples

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

Peak risk April–May along Wyoming's river corridors — the North Platte, Green, Snake, and Bighorn rivers all have cottonwood stands. The fluffy white seed release is unmistakable. The invisible pollen precedes the seeds by 3–4 weeks.

Range grass pollen

Tomatoes, potatoes & melons

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

Peak risk June–July across Wyoming's rangelands. Range grasses, wheat, and alfalfa contribute to summer pollen across the agricultural basins. Counts are lower than in high-production agricultural states like Kansas or Oregon.

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.