Where’s the worst pollen in South Florida? What a car test found
Did you wake up to a car covered in yellow dust?
Yes, your set of wheels needs a wash — and you may need some allergy meds.
Your car can be a barometer for pollen type and intensity in your neighborhood. That was the thinking of a University of Miami research team that tested the rear windshields on about 100 cars parked on the Miami campus of Jackson Health System.
The goal was to take a “snapshot in the peak of pollen season in Miami-Dade County,” said University of Miami Miller School of Medicine pollen expert Naresh Kumar.
He wanted to see what type of pollen is circulating in South Florida and making us miserable.
In early March, Kumar’s students flagged down drivers searching for parking on Jackson and UHealth’s shared campus and asked if they wanted a swab of their cars to test for pollen.
Then the cotton swab sticks, like the ones you stick up your nose to test for COVID, went to an on-campus lab for analysis.
So what did the researchers find on the cars?
“We are seeing dramatic variations in the concentration of the pollen in different parts of Miami-Dade County,” as well as different species of pollen, Kumar said in a phone interview after the analysis.
Pollen on the cars came mostly from live oak and also pine, palm, mango — typical trees in South Florida.
Because the cars come from various places in South Florida, Kumar’s team took note of driver’s home addresses and ZIP codes to reveal where the most pollen might be lurking.
The environmental health professor said two samples with the highest concentration of pollen from cars parked outside came from ZIP code 33133, which encompasses Miami’s lush Coconut Grove, and 33071, a swath of Broward County near the Florida Everglades bordered by Coral Springs to the north, Margate to the east and Tamarac to the south.
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Cars parked outside, and not in a garage, will usually be covered in more pollen. Those who live in areas with lots of trees, plants and flowers will likely see more pollen blown onto their car windows compared to those who park in coastal areas where the wind comes from the ocean, according to Kumar.
Cars usually spend the most time parked at home. This means there’s a high chance the yellow dust covering a person’s rear windshield comes from nearby trees, flowers and other pollen makers, Kumar said. But the researcher acknowledges that there’s also no guarantee that the cars only picked up the pollen in their own neighborhoods.
Still, Kumar says the experiment is a good reminder for people to learn what makes their eyes itch and their nose stuffy. That’s especially important in South Florida, where people tend to sniffle and sneeze from allergies year-round.
And if it’s not pollen making you sneeze, it could be mold, dust, pet dander and even seaweed.
MORE: Will pollen allergies get worse in South Florida as climate turns hotter?
This story was originally published May 7, 2025 at 8:25 AM.
