Does Temperature and Cloud Cover Affect Your Marathon Running Performance?

By Rick Morris

Most runners love to run on cool and cloudy days, but does temperature affect your marathon running performance. I have to agree that running seems more comfortable on days like that but do we really run better on gloomy days? There’s no question that high temperatures have an adverse effect on running performance, particularly marathon running performance. There have been many studies that have proven marathon running paces rise when the temperatures are hot, but is there a set of ideal weather conditions that are conducive to top marathon running performances?

I was always under the impression that an overcast sky would result in the best marathon running performance. It just seemed to make sense. A combination of cool temperatures and sun blocking cloud cover makes running easier and more comfortable – or so I thought. Once again I have been proven wrong. A study conducted by the US Army investigated the effect of cloud cover and low solar loads on marathon performance. The results were quite surprising. The army researchers looked at the finishing times and weather conditions for the winning performances of seven North American marathons. They found that cloud cover was not associated with a fast marathon and concluded that “The presence of cloud cover or low solar load does not increase the likelihood of running a fast marathon.”

The study did confirm that the common factor among fast performances was cooler temperatures, specifically between 51 and 55 degrees F for men and 53 to 57 degrees F for women. So forget praying for cloud cover during your next marathon and ask for nice cool temperatures instead.

The study confirmed what we really already knew – that cooler temperatures make for faster times. But, how about even colder temperatures. Is there an ideal temperature for marathon running? There probably isn’t one perfect marathon running temperature for everyone, but those same army researchers  suggest that temperatures that go beyond cool and into the cold category may give your marathon pace an even further boost. Using additional data from the same seven marathons the researchers compared the temperature with the finishing times of the 25th, 50th, 100th and 300th place finishers. They said that “There is a progressive slowing of marathon performance as ambient temperature increases from 41 degrees F to 77 degrees F. This seems true for men and women of wide ranging abilities, but performance is more negatively affected for slower populations of runners.”

Wow ! – The army researchers believe that the most ideal marathon running temperature is a numbing 41 degrees F! That’s bad news indeed for a warm weather fan like myself. There isn’t a lot of scientific data concerning the most ideal marathon running temperature and conditions but this study certainly opens some eyes. It looks like the best marathon running conditions just may be cold and clear. So head north for your next marathon and layer up!


Neither cloud cover nor low solar loads are associated with fast marathon performance, US Army Research Institute of Environmental Medicine, Med Sci Sports Exerc. 2007 Nov;39(11):2029-35

Impact of weather on marathon running performance, US Army Research Institute of Environmental Medicine, Med Sci Sports Exerc, 2007 Mar;39(3):487-93