Port Royal, SC 29905 Frost Dates
When can you plant in Port Royal, SC?
Around 03/03 is the usual last spring frost, about 187 days away. The first fall frost typically arrives around 12/09, about 282 frost-free days later.
Port Royal 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.
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.
The actual range around Port Royal's last frost
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 4,773 of 40,283 US ZIP codes measured here, longest to shortest. Within SC, it ranks 20 of 519.
Learn more
zone vs. frost date covers why Zone 9a and Port Royal's frost date answer different questions. the frost range covers how to read the range around Port Royal's dates instead of trusting one.