A new study published in PLOS ONE found that on rainy days, the number of negative Facebook posts increases by 1.16 percent, and the number of positive ones decreases by 1.19 percent. It isn’t just the wet weather making people cranky. The researchers also looked at the Facebook updates of the users’ friends in other cities to see if the bad feelings spread. Indeed, they found that for every negative post from rainy locales, there were 1.29 negative updates elsewhere in their extended networks, even where skies were clear. So next time you want to whine about the weather online, consider that you might be raining on someone else’s sunny parade.