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It's hotter in Boise than it used to be - here's why

Heat wave construction worker
Posted at 6:11 PM, Jul 31, 2022
and last updated 2022-07-31 20:11:22-04

BOISE — Hot days are more than just uncomfortable - they’re a threat to human life - especially for vulnerable populations like children and the elderly.

Extreme heat kills more Americans than any other weather event. Though heat waves are a natural part of day-to-day weather variation, as the earth’s climate warms due to global emissions they’re getting worse according to NASA Climate. Heat becomes more severe and frequent in a warming world.

Related: Dangerous Pacific Northwest heat wave suspected in 7 deaths
Related: Warming environmental conditions to continue

Boise is one of the fastest warming metropolitan areas in the country. In the past five decades the average summer temp has increased by 5.6 degrees.

Boise sees an increase in average summer temperatures

The city joins the ranks of two Nevada cities - Reno and Las Vegas - warming just as fast if not faster. +10.9 degrees and +5.9 degrees respectively.

But there’s another factor at play contributing to our warming. Boise is also one of the fastest growing areas of the country. The Treasure Valley gained 25,000 residents last year, reported by BoiseDev.

Urban development also contributes to an increase in heat due to a phenomenon known as "Urban Heat Island." Buildings, roads and other infrastructure absorb, hold and re-emit the sun’s heat back into the surrounding air way more than natural environments. With added urban growth comes added heat.

The City of Boise is working to combat this by planting 100,000 trees by 2030. So far, they’ve planted over 13,000 urban trees.

Related: City of Trees Challenge enters year 3 with new goals
Related: Mayor McLean on the City of Boise's climate progress: 'I'm optimistic'

More evidence of warming can be seen with how many days above normal Boise now sees in the summer: an increase of 32 days on average over five decades. This summer, we’ve already had 41 days above normal as of Sunday, July 31st.

Boise sees 32 days on average above normal in the summer