Longer Growing Season Means Longer Allergy Season In 172 Cities

It's Bad News For Allergy Sufferers

We’ll likely be saying “bless you” a few more times in the springs to come as temperatures warm and the growing season lengthens.

The growing season is now more than 50 days longer than it was in the 1970s in cities like Medford, Oregon, and Myrtle Beach, South Carolina, according to a new analysis from Climate Central. In Reno, Nevada, the season is now more than three months longer.

When we talk about the growing season, this is the period that is bookended by a lack of freezing temperatures. In the case of Reno, that means there are 96 more days between the last freeze of the spring and the first freeze in the fall than there were decades ago.

The biggest changes in growing season are found in the West, Southeast and Great Lakes. The smallest changes are in the Midwest to the Rockies.

The growing season lengthened in 87% of cities that Climate Central looked at and the season was lengthened by nearly three weeks on average across all cities.

(​MORE: Further beef up your forecast with our detailed, hour-by-hour breakdown for the next 8 days – only available on our Premium Pro experience.)

The Pollening Is Coming

Of course, growing plants means more pollen too.

This season is just beginning to bloom across the South as you can see below. Both tree pollen and grass pollen are pushing northward as temperatures warm.

After a slow start in Florida, these blooms are slightly earlier than average this year across parts of the South and Southwest, according to the National Phenology Network.

The longer growing season can mean days to weeks of extra sneezing, coughing, itchy and watery eyes and runny noses.

If you’re like me, that also means a lot of extra allergy medications.

(​HEALTH HUB: Find help for Psoriasis, Eczema and Diabetes here.)

Warmer Days Spur Longer Growing Season

Spring has warmed in nearly every city across the Lower 4, according to an analysis completed by Climate Central earlier this year.

Furthermore, spring has warmed by 2.4°F on average.

Spring has warmed the most in the Southwest and East. In areas shaded in the darkest salmon tones, temperatures have warmed at least 4°F in the last half-century.

These warmer temperatures don’t just cause more pollen, but they also worsen the risk of wildfires, bring more pests and cause less snow to fall in areas that need it for their water supplies.

Jonathan Belles has been a graphics meteorologist and writer for weather.com for 8 years and also assists in the production of videos for The Weather Channel en español. His favorite weather is tropical weather, but also enjoys covering high-impact weather and news stories and winter storms. He's a two-time graduate of Florida State University and a proud graduate of St. Petersburg College.