Pollen today
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Pollen today
Loading today’s values…
Google gave no index for tree, grass or weed pollen here today.
Next four days, highest level each day:
Source: Includes pollen data from GoogleGoogle Maps
Source: Includes pollen data from GoogleIncludes data from Google Maps
Google’s index for each plant it models in Chicago today. A plant out of season has no index.
Source: Includes pollen data from GoogleGoogle Maps
The forecast that moves pollen around, and the air beside it.
Forecast: National Weather Service, updated 10:31 am CT.
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Each thread is one kind of pollen, and each square is one week, colored by that week’s highest level.
Google has given no index for Chicago since records began on October 14, 2026.
Highest level each week, November 2025 to November 2026, from each day’s forecast.
Source: Includes pollen data from GoogleIncludes data from Google Maps
What this forecast doesn’t measure, and when to get help.
Google’s index covers tree, grass and weed pollen only, so there is no mold level for Chicago on this page. The National Allergy Bureau publishes pollen and mold counts measured at its stations. Our guides cover common molds such as Alternaria, Cladosporium and Aspergillus.
The forecast doesn’t cover allergens indoors either: dust mites, cockroaches, mice, cats and dogs. Our guides explain each one, starting with dust mites and cats.
An estimated 10.2% of adults in the city of Chicago have current asthma, according to the CDC’s PLACES estimate for 2023 (95% confidence interval: 9.1% to 11.2%). It is a statistical estimate from national survey data, not a count.
159 allergists enrolled in Medicare practice in the Chicago area: 1.69 for every 100,000 people, more than the 1.22 across the US. The count doesn’t show how soon you can get an appointment. See the doctors listed in the Chicago area, or how every state and metro compares.
AllergyNest count from CMS’s Doctors and Clinicians file (October 2026) and Census population estimates for 2025.
The geography, climate and plants behind each season here, with a source for every fact.
Cool breezes off Lake Michigan bring Chicago some relief from summer heat.2 The lake’s large thermal mass tends to moderate temperatures, giving the city cooler summers and warmer winters.2 The lake also tends to suppress summer precipitation.2 At O’Hare, a typical year has about 193 days between the last spring freeze and the first fall freeze.1
A USDA Forest Service study of the Chicago region, published in 2013, found the most common trees were European buckthorn, green ash, boxelder, black cherry and American elm.3 Illinois Extension lists allergenic trees in the order they flower: maple, willow, poplar, elm, birch, mulberry, ash, hickory, oak and walnut.4 These trees are usually a problem from March through May, and allergenic grasses such as orchardgrass, bluegrass and timothy bloom from May through summer.4
Illinois has two main ragweeds, common and giant.5 Common ragweed starts to bloom in July or August and peaks in September.5 Both species are on the state’s noxious weed list and must be controlled inside cities, villages and towns, though not in rural areas.5
Answered from the values on this page.
Very little. None of the plants Google models is above 0 in Chicago today.
No. It’s Google’s modeled pollen index, from 0 (none) to 5 (very high), calculated for the location of central Chicago. A pollen count is the number of pollen grains measured in a cubic meter of air at a counting station. How our pollen index works.
Twice a day. We fetch new values soon after midnight in Chicago, so each day starts with its own values, and again after Google’s daily model run, usually by about 9:30 am CT. Each section shows when its values were retrieved.
Source: Includes pollen data from GoogleIncludes data from Google Maps