Bad News If You Start Sneezing Once the Weather Warms

If your nose starts to run and your eyes start to itch as soon as spring hits, break out the Kleenex—allergy season isn't getting shorter anytime soon. In fact, it's getting longer in many cities across America, according to Climate Central's new analysis, which points the finger at climate change as a driver for this extended misery.

• Findings: The research group looked at National Oceanic and Atmospheric Administration data from nearly 200 US cities, from 1970 through last year, and found that the "freeze-free growing season"—the period of consecutive days with minimum temps above 32 degrees Fahrenheit, which Axios notes is used as a proxy for allergy season—has grown longer over that 50-year-plus span in 172 of those cities, or 87% of them. Those affected cities saw 20 days on average tacked on to their freeze-free periods.

• Explainer: So why are allergies getting worse with longer spring seasons? When the mercury is above the freeze level, plants are able to grow better, which means more pollen is released into the air, particularly from grasses and ragweed. The analysis notes that climate change is not only stretching allergy season out—it's also making it "more intense due to heat-trapping pollution."
• Hit hardest: Climate Central notes that cities in the Southwest and Northwest saw the biggest average jump, at 20 days and 24 days, respectively. Reno, Nevada, saw the largest increase, with 96 more consecutive freeze-free days, followed by Las Cruces, New Mexico (66 days) and Medford, Oregon (63 days).
• More evidence: The Independent cites data from the National Phenology Network indicating that the spring season's start, on average, has come earlier in the mainland US since 1984, and that total pollen amounts spiked more than 20% between 1990 and 2018.
• Where not to live if you're a spring sneezer: The Asthma and Allergy Foundation of America lists the nation's "allergy capitals," with the most recent warnings posted against Dallas; Wichita, Kansas; and Raleigh, North Carolina, among others.

(More allergies stories.)