Harvard hopefuls are under plenty of pressure to rack up internships, pen Pulitzer-quality essays, and patent an invention or two to stand out from the crowd. Unfortunately, when it comes to their admission chances, there’s still one variable they can’t control: the weather.

In a study of 682 admissions decisions, Wharton professor Uri Simonsohn found that application reviewers ranked academic achievements most important on cloudy days. But when the sun was shining, they gave more credence to nonacademic pursuits like sports.

The effect was surprisingly significant: A scholarly candidate’s chances of acceptance increased by an average of 12 percent when it was overcast. Short of applying to schools in Seattle, there’s not much you can do to take advantage of this effect, except know that you can blame any rejections on good weather.