Technical Abstract: Pacific white shrimp (Litopenaeus vannamei) culture in low-salinity water in inland ponds is expanding throughout the southern United States and pond culture generally is limited to early May through late October, except in the southern-most region of the country. Cold fronts can move in quickly, both in the spring and fall, and their impact can last for a number of days before moderating. Low nighttime air temperatures can result in low water temperatures, such that water temperatures possibly can drop to the lethal limit of L. vannamei during a prolonged cold front. We calculated probabilities of a minimum air temperature less than or equal to 14 C occurring on one day, and three or five consecutive days and report these probabilities for the stocking and harvest seasons at each site. One-hundred-year datasets of minimum air temperature were obtained for sites in the southern US where L. vannamei is or could be cultured in ponds. Selected sites were: Arcadia, FL; Gila Bend, AZ; Greensboro, AL; Hattiesburg, MS; Pecos, TX; Pine Bluff, AR; Portland, AR; Tifton, GA. A minimum nighttime air temperature less than or equal to 14 C can cool water enough to kill shrimp. The probabilities of one, three or five consecutive days with a minimum air temperature less than or equal to 14 C is high (50%) from late-March through late-April at all sites except Arcadia. Probabilities drop to 10% for the three scenarios by early-May to early-June. In the autumn, the 10% probability level is reached in early- to mid-September and the 50% probability level is reached by late-September to mid-October. Arcadia has the longest period with low probabilities of low minimum air temperatures and Pecos has the shortest.