As anyone who's been caught in a downpour without an umbrella knows, predicting the weather is no simple task. This is especially true of long-term forecasting. Yet since 1818, the Farmers' Almanac—published annually from its Lewiston, Maine offices—has been trying to do just that for the continental United States. Can you really predict the weather a year from now?

Penn State meteorologist Paul Knight is more than a little skeptical.