Report · 2026 season

The Worst US Cities for Allergies in 2026

Allergy season hits some metros far harder than others. Using our seasonal pollen model — calibrated to grass, tree, and weed peaks per latitude — we ranked the top US cities by combined peak pollen for the 2026 season.

How we ranked

For each city we computed the highest single-day grass, tree, and weed pollen counts expected this year (grains per cubic meter), then summed those peaks. Cities with the largest combined peak rank as the most difficult places to live with allergies.

Top 25 worst cities

#	City	Grass	Tree	Weed	Combined
1	SeattleWA G 113 · T 146 · W 98	113	146	98	357
2	PortlandOR G 111 · T 144 · W 97	111	144	97	352
3	MinneapolisMN G 111 · T 143 · W 96	111	143	96	351
4	MilwaukeeWI G 110 · T 142 · W 95	110	142	95	346
5	BostonMA G 109 · T 141 · W 95	109	141	95	345
6	DetroitMI G 109 · T 141 · W 95	109	141	95	345
7	ChicagoIL G 109 · T 141 · W 95	109	141	95	344
8	OmahaNE G 108 · T 140 · W 94	108	140	94	343
9	ClevelandOH G 109 · T 140 · W 94	109	140	94	343
10	New YorkNY G 108 · T 140 · W 94	108	140	94	341
11	PittsburghPA G 108 · T 139 · W 94	108	139	94	341
12	Salt Lake CityUT G 108 · T 140 · W 94	108	140	94	341
13	PhiladelphiaPA G 107 · T 139 · W 93	107	139	93	340
14	ColumbusOH G 107 · T 139 · W 93	107	139	93	340
15	IndianapolisIN G 107 · T 139 · W 93	107	139	93	339
16	DenverCO G 107 · T 139 · W 93	107	139	93	339
17	BaltimoreMD G 107 · T 138 · W 93	107	138	93	338
18	Kansas CityMO G 107 · T 138 · W 93	107	138	93	338
19	CincinnatiOH G 107 · T 138 · W 93	107	138	93	338
20	WashingtonDC G 107 · T 138 · W 93	107	138	93	337
21	SacramentoCA G 107 · T 138 · W 93	107	138	93	337
22	St. LouisMO G 107 · T 138 · W 93	107	138	93	337
23	LouisvilleKY G 106 · T 137 · W 92	106	137	92	336
24	San FranciscoCA G 106 · T 137 · W 92	106	137	92	335
25	San JoseCA G 106 · T 136 · W 92	106	136	92	334

When peaks hit

Tree pollen leads the season — most cities peak in April as oaks, birches, and olives release. Grass surges through June, and weed pollen — driven heavily by ragweed — usually crests in September. Higher latitudes tend to amplify these peaks because longer growing days push more pollen into the air during a compressed bloom window.

What to do if you live in a top-ranked city

Track your local daily count — check the Pollen Count Graph homepage for your zip code.
Keep windows closed during the peak month for the pollen type you react to.
Shower and change clothes after outdoor time on high-count days.
Start antihistamines a week or two before your city's expected peak.

Methodology & caveats

Counts come from our seasonal model derived from Open-Meteo's air quality history, adjusted for hemisphere and latitude. They represent expected peak daily values, not measured station data, and conditions can vary year to year with weather. For live counts in your city, search by zip on the homepage.