Punxsutawney Phil, Pennsylvania’s famous weather-forecasting rodent, might be a beloved herald of spring, but a better indicator of impending warmer weather is when home improvement stores start unveiling sales specials and bulking up their in-store workforces.

To do so effectively and efficiently requires these retailers to stay on top of national weather patterns during their peak selling season for the year. After all, if there's a rush on snow shovels this weekend in the Northeast due to Winter Storm Nemo, which threatens to dump as much as two feet of snow on Boston, retailers better have dispatched the stock and planned staff schedules ahead of that demand. And if the weather improves a few weeks later, better have shopper-attracting sales on BBQ grills and gardening equipment ready.

Atlanta-based Home Depot (NYSE:HD) came out on Wednesday with its annual seasonal hiring number: It said 80,000 workers will be hired to meet the demand of Americans consumers who crawl out from their winter holes to gaze upon gardens in need of mulch, ice-battered gutters, siding that needs repair or other tasks to add to their springtime to-do lists.

Home Depot’s announcement comes two weeks after rival Lowe's Companies Inc. (NYSE:LOW) of Mooresville, N.C., said it was hiring 45,000 seasonal workers and 9,000 permanent part-time associates to help on the weekends, or 12.5 percent more workers than last season.  

Together the country’s two largest do-it-yourself retailers will hire 134,000 seasonal workers, 14 percent more than they hired last year.

"Spring is always a special season for us,” said Tim Crow, Home Depot’s head of human resources.  

Unlike other retailers, which see their best business in the last three months of the calendar year, home improvement stores big and small see their best business in the earlier months of the warmer part of the year, roughly peaking as hot weather begins and petering out toward the dogs days of summer.

This annual shopping event is unique because, unlike the peak end-of-year shopping season for retail, this end-of-winter consumer buying spree begins in the southern, balmier parts of the country first, and then gradually moves up the continent as winter weather retreats. The hiring, stocking and sales specials chase the receding cold. In fact, this may well be the only perennial shopping season that behaves in this manner.

“We have a very close working relationship with weather experts that give us information about climate trends, and those are factored in how we are looking at certain parts of our business,” said Karen Cobb, a Lowe’s representative. “It’s not a sole deciding factor, but we look at what the long-term weather predictions are and take these into consideration. The weather acts like a barometer -- excuse the pun -- for stocking our stores with certain products and for anticipating our staffing needs.”

Lowe’s even has its own emergency command center that monitors unusual weather patterns in order to predict which stores should stock up on what products — and to do so before the storm hits.

“For instance, we’re watching the weather patterns in the Northeast right now to anticipate the needs of our customers there,” said Cobb.

Predicting the weather is a difficult game, but also an important one in this segment of the retail industry. If this weekend’s winter storm blankets the Northeast as predicted, then before this happens regional home improvement stores need to stock up on products like snow shovels and space heaters. And it takes more than a rodent from Pennsylvania to make those kinds of heady predictions.