Which Denver schools have the hottest temperatures, and how could millions of dollars cool them off?

In Denver, school starts before summer officially ends. When students file back into classrooms in August, taller and perhaps more eager than when they left in June, the temperature outside is often still in the mid-80s — and the temperature inside can be even hotter.

A survey conducted in September found that building temperatures reached as high as 94 degrees, with a total of 50 schools above Denver Public Schools’ comfort goal of 79 degrees.

That’s why a committee of parents, students, teachers and taxpayers is recommending the district ask voters in November to approve raising $70 million in taxes for heat mitigation as part of a $572 million bond that would pay for a variety of construction and maintenance projects.

“When we saw some of the temperatures were at 88 degrees and 84 degrees, we were all surprised and said, ‘Yes, this is where we can really make a big impact,’” said Lauri Dannemiller, co-chair of the subcommittee that examined school temperatures.

“Some folks could say, ‘Kids are in school when it’s that hot maybe 30 days a year,’” she said. “But the reality is that you have to make those investments because every day counts.”

The bulk of the $70 million — $44 million — would be spent on automated nighttime air exchange systems that push hot air out and pull cool air in for the 79 schools without full air conditioning, according to Dustin Kress, the district’s manager of bond and mill levy programs. Another $5 million would be earmarked for repairing broken cooling systems. And $21 million would be spent on classroom air conditioning for the district’s 18 hottest school buildings.

All but two of those buildings serve a majority of low-income kids. In 12 of the 18 buildings, some of which house more than one school, the number of students who qualify for free or reduced price lunch, a proxy for poverty, exceeds the districtwide average of 69 percent:

“Teachers can’t teach when it’s that hot,” Dannemiller said, “and kids can’t learn.”

Her assertion is backed up by research — much of it decades-old — and a DPS case study. The district looked at the test scores of elementary school English language learners who took classes last summer in schools with and without air conditioning. Not taking into account the quality of the teachers, the district reported that students in schools with air conditioning did better.

In addition, DPS surveyed school administrators last fall at the 79 schools without full air conditioning. A whopping 83 percent said the temperature inside their buildings during the hottest weeks of the year was uncomfortable and impacted instruction.

Complaints about DPS schools being too hot are nothing new. In 2011, when a heat wave sent outdoor temperatures soaring into the mid-90s for the first two weeks of school, parents started a petition asking the district to push back the start of school until after Labor Day.

In a newsletter titled “Too Darn Hot,” Superintendent Tom Boasberg agreed to look into it. The school board eventually voted to delay the start of school by a handful of days.

Today, 73 DPS school buildings have full air conditioning, which is fewer than those that don’t. Many of them are located in the northeast Denver neighborhoods of Stapleton, Montbello and Green Valley Ranch, which are among the newest parts of the city and have newer schools.

Overall, 45 percent of DPS students go to school in buildings with full air conditioning, while 55 percent do not, according to the district. If voters pass the bond, officials said the heat mitigation efforts should bring the temperature of all the district’s schools down to at least 79 degrees.

The $572 million bond proposal would pay for other projects as well, including building new schools and renovating old ones. Due to rising property values and decreasing debt, DPS figures it can raise that amount without increasing the current tax rate.

The committee is also recommending the district ask voters to approve raising $56.6 million to pay for the expansion of successful programs. Doing so would cost taxpayers an estimated additional $110 per year for a Denver home valued at $329,000, according to DPS.

The Denver school board is set to hear public comment on all of the recommendations this evening, discuss them at a work session Monday and vote on them June 16. If they approve them, voters would be asked in November whether to raise the requisite taxes.

Is your school in one of the 79 buildings without full air conditioning? Curious about the temperature there? Consult our chart below.

But first, a couple of caveats: Not all of the numbers are based on the same volume of data. Although DPS asked its facility managers to measure the temperature in the hottest part of their school buildings at the hottest part of the day over multiple days, not all of them did. In some instances, a school’s average temperature is based on a single reading.

Not all schools are represented. When possible, the district used “sister building” data: temperature readings from a school of roughly the same age, height and directional orientation. We’ve flagged those instances.