New NWEA Research Examines Impact of Heat on Academic Outcomes

Study finds math is more impacted by higher temperatures than reading – especially for students in high-poverty schools

PORTLAND, Ore., Oct. 23, 2025 /PRNewswire/ -- NWEA, a K-12 assessment and research organization, released today a new report examining the impact of environmental temperatures on student performance in math and reading, and whether those effects are more extreme for students in high-poverty schools, where cooling conditions may be less reliable.

The new research report titled "Hot test days, lower math scores: How heat affects student achievement" used recent, large-scale student test scores from NWEA's MAP Growth assessment (used by more than 35,000 schools across 146 countries) for grades 3 through 8 across six states in various regions of the country. This provided approximately three million tests from fall testing sessions in 2022, 2023, and 2024. The scores were then compared against daily temperature data from the National Oceanic and Atmospheric Administration (NOAA), data from the school location, and other characteristics from the Common Core of Data (CCD).

The main finding: Math outcomes suffer more in higher temperatures.

• Test-day temperatures over 80° were associated with lower MAP Growth scores in math but not reading. Even when temperatures weren't extreme, testing on a day that was unusually hotter than average was associated with slightly lower math test scores. More specifically, math test scores were about 0.05 standard deviations lower when temperatures ranged between 81°F to 100°F, and 0.06 standard deviations lower on days above 101°F. In other words, students who tested on a 101°F day scored roughly 0.06 standard deviations below students who tested on a 60°F day. To put these results into context, 0.06 standard deviations is the equivalent of about 10 percent of the learning typically gained in a school year for a fifth-grader.
• High heat had up to twice the impact on students' math scores in high-poverty schools compared to low-poverty schools.

"Extreme heat doesn't affect all students equally – on test days where temperatures spike above 80 degrees, math scores drop the most for high-poverty students," said Sofia Postell, research analyst at NWEA. "Our findings show that as temperatures continue to rise, disparities in school facilities, such as having appropriate HVAC systems, can deepen existing inequities and make school infrastructure and building conditions significant issues of educational equity."

The report provided several recommendations for district and school leaders, including:

• Planning testing schedules around weather conditions
• Selecting testing locations within school locations that maintain more stable temperatures
• Investing in more resilient facilities in the long term
• Ensuring that infrastructure planning considers resource allocations, structural improvements, and upgrades that take educational equity into account.

Read the new report at https://www.nwea.org/research/publication/hot-test-days-lower-math-scores-how-heat-affects-student-achievement/

About NWEA

NWEA ^®  (a division of HMH) is a mission-driven organization that supports students and educators in more than 146 countries through research, assessment solutions, and professional learning that support our diverse educational communities. Visit NWEA.org to learn more about how we're partnering with educators to help all kids learn.

Contact: Simona Beattie, Communications Director, [email protected] or 971.361.9526

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SOURCE NWEA