If every cloud has a silver lining, a recent study suggests that this may be particularly true for universities.
According to research published in the latest edition of The Economic Journal, students who visit a university on a cloudy day are more likely to choose to study there.
The finding follows previous research showing that decisions about the future are often based on experience of the present - for example, shoppers are likely to buy more groceries if they shop when hungry.
Uri Simonsohn, assistant professor at the Wharton School, University of Pennsylvania, wanted to examine whether the same "deviations from rationality" apply to high-stakes decisions such as selecting a university.
He analysed weather patterns and the enrolment decisions of 1,284 prospective students who visited an institution known for its academic strength. He found that an increase in cloud cover of one standard deviation on the day of the visit was associated with an increase in the probability of enrolment of 9 percentage points.
This is consistent with the idea that gloomy weather increases the appeal of academic activities, he said.
"When you think about it, it kind of makes sense," said Professor Simonsohn, whose paper is titled "Weather to Go to College". "To some extent, you do feel less guilty if you are working hard if it is not appealing to be outdoors.
"If it is cloudy and raining outside, you don't mind reading. If it is beautiful and sunny, you feel like you are not doing what you are supposed to be doing with your time."
He said it was interesting that, in a short visit, a "transparently irrelevant transient factor" such as cloud cover could have a large impact.
While universities cannot control the weather, the study suggests that when organising open days, institutions should think hard about what potential students hoped to experience during their time at university.
Professor Simonsohn said: "In business schools, social networks are very important. So when a business school has prospective MBA students visiting, perhaps they should give them the feeling of a network by having alumni meet with them, for example."
Survey results published last week underline the importance of open days in student decision-making.
More than half of students (55 per cent) who responded to the Sodexo-Times Higher Education University Lifestyle Survey 2010 made their choice after a visit to the university, making open days the most influential non-academic factor.
More than a quarter (28 per cent) said their experience of an open day was the deciding factor in choosing where to study.
A previous paper by Professor Simonsohn, titled "Clouds Make Nerds Look Good: Field Evidence of the Influence of Incidental Factors on Decision Making", published in the Journal of Behavioral Decision Making, found that on cloudy days, admissions staff judged the attributes of applicants differently.
More weight was given to applicants' academic attributes on cloudier days, while their non-academic attributes were rated more highly when it was sunny.