When it comes to bold weather-related boasts, it's hard to beat the U.S. Postal Service's unofficial motto: "Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds." Yet even the USPS pales beside the standard set by the New York Stock Exchange: Wall Street hasn't closed for weather since 1985, when Hurricane Gloria tore its way through New England.

This isn't to say that the Exchange plays Russian roulette with the safety of its employees: On Feb. 8, 1994, it closed a few hours ahead of schedule because of a brutal snowstorm. Similarly, it delayed opening by a couple of hours on Jan. 8, 1996, when another horrifying storm made it near impossible to get into the office. Still, with precious few exceptions, the exchange has kept to its schedule, at least since central air conditioning made it possible for brokers to conduct business without passing out from the city's brutal summer heat.

But, while the Stock Exchange displays impressive determination and grit, it is also located on a low-lying section of lower Manhattan, right on the edge of "Zone B," the area that is expected to flood if Irene is still a Category 2 or higher when it hits New York. To make things worse, New York's subways habitually malfunction during comparatively mild rain showers, and the city's Metropolitan Transit Authority has already announced its plan to shut down the city's trains, bridges and buses before the storm even hits. If the city gets the storm surges and brutal rainfall that some meteorologists are predicting, it's hard to predict when the transit system will be back to full service; by most estimates, service will still be limited on Monday.

Still, there's no beating determination: A NYSE Euronext spokesman affirms that the the venerable institution plans to be open on Monday. "We have contingency plans in place for such events with the goal of having the market up and running while ensuring the safety of our people," he said. These plans include a back-up generator at the exchange's 11 Wall Street location, complete with extra fuel, that will enable the exchange to keep going. For traders and employees who brave the weather, the kitchen has laid in extra supplies of food.

Even if 11 Wall Street closes, trading will go on. Most trading is electronic, and the NYSE's computer facilities -- like its massive 400,000 square foot data center in Mahwah, NJ -- are expected to remain unaffected by Hurricane Irene. Similarly, other exchanges -- like the Nasdaq and the NYMEX -- are expected to stay open for business, using servers that are located off-site. In other words, even if the stock market's physical location gets a little flood, America's equities trading will continue to tread water.

Bruce Watson is a senior features writer for DailyFinance. You can reach him by e-mail at bruce.watson@teamaol.com, or follow him on Twitter at @bruce1971.