In recent years, cities across the United States have faced longer and more intense heat waves, presenting unexpected challenges for schools. Extreme heat doesn’t just make students uncomfortable; it can affect their ability to concentrate, perform, and learn.
Since many schools still lack adequate cooling infrastructure, educators may wonder how heat waves affect learning. My colleagues and I recently studied the impacts of hot test days on math and reading test scores. We found that extreme heat has serious implications for education and can influence how students perform on assessments.
How might heat affect learning?
Beyond the physical discomfort and reduced concentration that a warm classroom can cause, we know from research on this topic that heat can take a real toll on learning, ultimately affecting both short-term and long-term outcomes. Heat affects student outcomes when actual testing overlaps with high temperatures, particularly affecting math scores. In addition to heat on testing days, high temperatures over the course of a school year have also been shown to negatively affect student achievement, especially when much of learning occurs in inadequately cooled classrooms.
In our study, we focused specifically on the former: whether the temperature on the day students test is associated with achievement.
Do students score lower on hot test days?
In our analysis of students in third to eighth grade across six states, we found that math scores were meaningfully lower on hotter testing days, with the largest effects occurring when students tested on a day that reached temperatures above 80°F. Specifically, test-day temperatures above 100°F were associated with roughly a 0.06 standard deviation (SD) decrease in math scores.
Put another way, students who tested on a 101°F day scored roughly 0.06 SD below students who tested at 60°F. To contextualize this finding, 0.06 SD is the equivalent of about 10% of the learning typically gained in a school year for a fifth grader.
Reading scores showed little evidence of similar effects, but other research has shown similar differences between subjects.
Relative heat also matters
Since not all schools experience testing day temperatures as high as 100°F, we also looked at whether relatively hotter temperatures on a testing day (compared to other testing days at a school) also affected scores. We found that even days that are 10 degrees warmer than normal for a school were associated with slightly lower math scores. This suggests that, in addition to extremely high temperatures on testing days, even a relatively warmer testing day can affect student outcomes.
Which students are most affected?
Importantly, we found in our analysis that students who attended higher-poverty schools experienced larger declines in test scores on hotter testing days. Specifically, the effects for these students were roughly twice as large as for students in low-poverty schools. While our analysis did not measure whether air conditioning was turned on and working at the time of testing, the findings suggest that the environments in which testing occurred may exacerbate these decreases in test scores. In schools without reliable HVAC, the harmful effects of heat may mask students’ true achievement due to unequal testing conditions.
As heat waves become more common, it is essential that schools are able to mitigate environmental conditions present on important testing days. Testing conditions can be detrimental to performance, masking students’ true achievement and the amount of material they actually learned.
Key takeaways: What educators should know
Below are the key findings from our study:
- Hot test days are associated with lower math scores.
- Students in high-poverty schools experienced the largest declines in test scores due to high temperatures on test days.
- Testing conditions are one factor educators should consider when planning testing schedules.
- Improving school facilities may help reduce the effects of extreme heat.
How to learn more
To learn more about how heat may affect assessment outcomes in your school or district, I encourage you to read our research brief on the effects of test-day heat, “Hot test days, lower math scores: How heat affects student achievement.” For more Teach. Learn. Grow. articles on how weather plays a part in education, see “How to meet student needs following inclement weather–related school closures” and “What do we know about remote learning snow days?”
