A map of Yelp’s 100 top-rated restaurants. Surprise! A lot of them are in warm places.

If you live on the East Coast and were planning to dine out for dinner tonight, you might wanna reconsider. According to Weather.com, it’s supposed to rain here through much of the evening — and according to researchers at Georgia Tech and Yahoo Labs, we usually like our food less when it rains.

That was one of the conclusions, at least, from a new paper appropriately titled “Demographics, Weather and Online Reviews.” The study analyzed 1.1 million online reviews of 840,000 restaurants, looking for exogenous — or external — factors in the data. In other words, they wanted to figure out what makes us like or dislike a restaurant, beside the restaurant itself.

The results can be surprising. The diners’ education levels? No effect on actual ratings. Population of the area? Again, not so much.

But reviewers consistently gave worse ratings when it was raining or snowing outside than when it was clear. And reviewers usually liked restaurants better on warm and cool days, rather than very hot or very cold ones.

In researcher Saeideh Bakhshi’s words: “The best reviews are written on sunny days between 70 and 100 degrees … a nice day can lead to a nice review. A rainy day can mean a miserable one.”

There’s a bit of impreciseness inherent in the whole weather thing, of course; the researchers are technically looking at the weather at the time when the review was posted, which might not be the same time the reviewer dined at the restaurant. (When was the last time you finished a meal and immediately rushed to Yelp?)

Still, this is the first study to look at exogenous factors in online reviews, which makes it a fascinating glimpse into both the Internet hivemind and the forces that quietly shape our feelings, on the Internet and off it.

It also helps explain some of the more confounding front-runners in Yelp’s recent list of best restaurants. Most of the winners were in California and Hawaii. Maybe because it’s sunny and warm there all the time…?