Our endless mosquito season
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It's not your imagination. The mosquitoes are getting worse.
Driving the news: The number of "mosquito days" — that is, those with the hot and humid weather the flying insects crave — has trended upward in Indianapolis over the past several decades, Axios' Alex Fitzpatrick and Kavya Beheraj report.
- A new analysis from nonprofit climate science research organization Climate Central, defines a "mosquito day" as one with average relative humidity of 42% or higher, plus daily temperatures of 50°–95° F.
Why it matters: Mosquitoes are more than just a nuisance — they're a public health threat, carrying diseases such as malaria, West Nile and Zika, among others.
By the numbers: Indianapolis had 149 mosquito days in 2022, compared with 130 in 1979 — an increase of 19 days when conditions are ripe for the blood-sucking insects to join you in the backyard.
- 71% of the 242 locations Climate Central analyzed saw an increase in mosquito days between 1979 and 2022, of about 16 days on average.
The big picture: We're hitting peak West Nile virus season, a period when the Marion and Hamilton county health departments put out mosquito traps and urge residents to eliminate standing water on properties, such as clogged gutters or old tires.
Of note: Weather factors, such as rainfall and drought, can influence mosquito activity.
- They breed in pools of standing water, common after major storms.
- Mosquito habitats have been somewhat constrained this year because of drought conditions across Central Indiana.
Zoom out: Some locations — particularly in the South — are actually getting too hot for mosquitoes.
- They don't thrive in temperatures above 95° F — an increasingly common reading in southern summers.
The bottom line: Mosquitoes — and the diseases they sometimes carry — are shaping up as one more climate change-induced problem to worry about.