Mark Twain once said he counted 136 kinds of weather in a single New England day. If he were around today, he’d probably be tuning in to his local TV station and going online for help with the task.

Twain would have plenty of company. A nationwide survey just out from the National Center for Atmospheric Research (NCAR) found that nearly nine in 10 American adults check weather reports regularly. That adds up to about 300 billion forecasts annually.

The study is the first to comprehensively assess the public’s perception, use and value of forecasts. It appears in the June issue of the Bulletin of the American Meteorological Society. The work was funded by the National Science Foundation and National Oceanic and Atmospheric Administration.

The online survey of 1,520 Americans, conducted in November 2006, found that most people trusted and were generally pleased with the reports they received—at least those for weather less than three days ahead.

Although the authors note the difficulty in placing a dollar amount on the information, households reported an average value of about 10.5 cents for each forecast. Annually, this would total more than $31 billion, or about six times the actual cost of providing forecasts. “Americans are getting a good deal,” said the study’s lead author, Jeffrey Lazo, in a statement.

The authors, like Twain, found people have a general fascination with the weather that goes far beyond wanting to know whether or not to grab an umbrella on the way out the door.

The big question for many lately: Will the rain ever stop? Last week, an Associated Press reporter asked Ed O’Lenic of the federal Climate Prediction Center if El Nino is to blame for the unusually wet June. “Good question,” O’Lenic replied. Global warming? “We don’t know,” he said.  When will the deluge end? O’Lenic couldn’t say, so the reporter resorted to quoting Credence Clearwater Revival: “And I wonder, still I wonder, who’ll stop the rain.”

Photo by tourist on Earth, via Flickr.