HANOVER TOWNSHIP, Pa. – Bill Kirk’s company predicted a warm summer for 2005 – in 2004.

As spring blended into summer with a string of cooler-than-normal days, an executive at Wal-Mart, Kirk’s biggest client, began to panic.

He essentially called and asked: “Are you sure about the hot summer?”

Kirk replied yes.

“I remember the call vividly,” says Kirk, sitting in his office at Weather Trends International Inc. “I said, ‘No change in the forecast.’ “

Wal-Mart bought extra air conditioners. The summer of 2005 turned out to be the 10th warmest on record, Kirk says, and Wal-Mart sold out – to the jingle of some $130 million.

“One decision, one call, big win,” says the smiling Kirk.

He has good reason to be merry in any kind of weather. Weather Trends, which Kirk and Executive Vice President Jack Grum founded about five years ago, has become a go-to source for providing retailers and other businesses with forecasts that help them manage inventory and improve the bottom line.

Weather Trends’ offices are on the top floor of a handsome, three-story building. Some 17 people work for Weather Trends, but you would never know it. About half the work force handles sales, while most of the other workers inside include meteorologists who work on digesting historical data and producing reports.

The company uses a “statistical math-based approach” in its forecasting, which means Weather Trends reviews meteorological information going back 100 years or more to look at trends.

Kirk says weather patterns repeat year over year less than 20 percent of the time. He says Weather Trends’ forecasts, which take into account longer-term weather cycles, are at least three times more accurate.

While most people think of weather in terms of day to day, retailers look at year-ahead projections to decide their purchases or sales, according to Kirk.

It can mean the difference between a solid or soft financial quarter.

Clients pay up to $250,000 for the cornucopia of climatic data turned out by Weather Trends, according to Kirk.

“We understand more how retailers work,” says Kirk, who earned a bachelor’s degree in meteorology from Rutgers University and developed forecasts while in the Air Force. “With a retailer, you’ve got billions of dollars at risk because of the weather.

“I help companies de-risk their plan as it relates to weather. For all these big guys, it’s huge.”

In addition to Wal-Mart, Weather Trends’ customers include The Bon-Ton Stores Inc., which has been a “pretty consistent client” of Weather Trends for several years, according to Ed Carroll, Bon-Ton’s executive vice president of sales promotion and marketing.

Weather, says Carroll, is a factor that goes into the planning process for most retailers. Look at earnings news releases of publicly held companies; nearly all of them cite the weather in up or down quarters.

He says Weather Trends’ information has been reliable.

“It’s not going to be the end-all, but certainly, we are going to look at it in terms of how we’re flowing inventory,” says Carroll.

Teresa M. McCarthy, an assistant business professor at Lehigh University, sees business-statistical forecasting done by businesses such as Weather Trends as a viable option in retailing.

“Any valuable information you can add to reduce the forecast error will only result in reduced costs or increased revenues,” says McCarthy, who also worked 14 years in retail management.

“The more accurate you can get it, the better performance you are going to have.”

Weather Trends also sells information to institutional clients in retailing and elsewhere, including Citigroup and Merrill Lynch, which track the fortunes of the retailing stock companies.

The business has about 50 customers, according to Kirk, whose rapid delivery hardly belies his passion for weather. It can provide forecasts for 129 countries and hopes to grow the business worldwide. The company raised $4.5 million last year from venture capitalists to help it reach the goal.

“Jack and I, we wanted to expand globally,” says Kirk, referring to Vice President Jack Grum. “We really thought we had the greatest thing since sliced bread.”