Los Angeles and Phoenix experience the widest range of temperatures during a summer day, while Seattle registers the lowest temperature range among 20 cities that Geotab analyzed for its "Heat in the City" report culled from fleet vehicles using the company's telematics devices.

Los Angeles registered a high of 108 degrees and a low of 71 degrees Fahrenheit, which represented a variance of 37 degrees. Phoenix saw a high of 115 degrees and a low of 85 degrees, which represented a variance of 30 degrees. Seattle saw an 8 degree variance with a high of 70 degrees and a low of 62 degrees. The data was collected at noon on June 21, 2017 from vehicles using the Geotab GO device at more than 55,000 points.

Five other cities saw a variance of at least 20 degrees, including Houston, San Diego, Dallas, Minneapolis, and New York.

The report also analyzed Boston, Chicago, Denver, San Francisco, Philadelphia, Atlanta, Baltimore, Detroit, Miami, St. Louis, Tampa, and Washington, D.C.

"As cities across the globe expand, having visibility into temperature patterns may become increasingly important for municipalities committed to creating energy-efficient urban environments and smarter cities," said Mike Branch, Geotab's vice president of data and analytics. "By leveraging data such as hyper-local temperature data, cities are not only equipping themselves with the tools to make progressively informed decisions, but build safer and more sustainable communities for all."

Geotab looked at the 20 most populous cities in the U.S. based on 2016 Census data.