Port Royal, SC 29904 Frost Dates
Port Royal, SC: when does the frost end?
Around 03/03 is the usual last spring frost, about 187 days away. Fall's first freeze usually shows up around 12/09, roughly 282 days after the last spring frost.
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.
Stretching the season past the first frost
With roughly 15 weeks until Port Royal's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
03/03 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 03/20 and only about 1 year in 10 sees frost after that.
Port Royal against the rest of the dataset
At roughly 282 frost-free days, Port Royal places 4,772 of 40,283 ZIP codes in this dataset. Within SC, it ranks 19 of 519.
Learn more
Before leaning on 29904's figures: zone vs. frost date explains why Zone 9a and Port Royal's frost date answer different questions, while the frost range explains how to read the range around Port Royal's dates instead of trusting one.