Simpson, LA 71474 Frost Dates
71474, near Simpson, LA: the frost window
Typically, the last spring freeze lands around 03/01, roughly 185 days out. Fall's first freeze usually shows up around 11/23, roughly 268 days after the last spring frost.
Simpson sits in USDA Zone 9a (20 to 25°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Simpson's growing season runs out in roughly 12 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 03/01 isn't a guarantee
03/01 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/31 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 03/24 and only about 1 year in 10 sees frost after that.
Simpson against the rest of the dataset
Simpson's growing season runs about 268 days, ranking 5,812 of 40,283 US ZIP codes measured here, longest to shortest. Within LA, it ranks 415 of 710.
Learn more
Two guides worth reading on 71474: zone vs. frost date, on why Zone 9a and Simpson's frost date answer different questions, and the frost range, on how to read the range around Simpson's dates instead of trusting one.