Port Royal, SC 29901 Frost Dates
When can you plant in Port Royal, SC?
Typically, the last spring freeze lands around 03/03, roughly 187 days out. The first fall frost typically arrives around 12/09, about 282 frost-free days later.
The USDA Plant Hardiness Zone Map puts Port Royal in Zone 9a (20 to 25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 15 weeks of growing season left in Port Royal before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 03/03 isn't a guarantee
03/03 is the middle of 30 years of NOAA records, not a promise. Plant by 02/02 and you're betting against frost in roughly 9 years out of 10. 03/20 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Port Royal compares
Port Royal's growing season runs about 282 days, ranking 4,771 of 40,283 US ZIP codes measured here, longest to shortest. Within SC, it ranks 18 of 519.
Learn more
the frost range covers how to read the range around Port Royal's dates instead of trusting one. local microclimates covers what one yard in Port Royal can differ from the 29901 normal.