When to plant in Port Royal, SC
USDA Zone 9aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Port Royal, South Carolina — all computed from Port Royal's nearest NOAA weather station.
A generous ~281-day season lets Port Royal gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Zone 9a is warm enough that Port Royal can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
Frost probability
BEAUFORT WWTP · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Port Royal’s own odds, recorded at BEAUFORT WWTP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 1 | Mar 16 | Feb 27 | Nov 10 | Nov 26 | Dec 15 |
| 32°F | Mar 20 | Mar 3 | Feb 2 | Nov 21 | Dec 9 | Jan 4 |
| 28°F | Mar 11 | Feb 9 | Jan 9 | Dec 3 | Dec 28 | Jan 21 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.
Full-year planting calendar
Each bar is the exact window to take a planting action in Port Royal, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 41 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Port Royal planting FAQ
When is the last spring frost in Port Royal, SC?
On average, the last spring frost in Port Royal is around March 3 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in Port Royal, SC?
The first fall frost in Port Royal typically arrives around December 9 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Port Royal in?
Port Royal is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Port Royal?
There are roughly 281 frost-free days in Port Royal (a long growing season), running from the average last frost around March 3 to the first fall frost near December 9.
When should I plant tomatoes in Port Royal?
In Port Royal, start tomato seeds indoors around January 6–January 20, then transplant seedlings outdoors around March 10 once the danger of frost has passed.
Never miss a window in Port Royal
An email when it’s time to start seeds, transplant, and sow — timed to Port Royal’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Beaufort · 12 km
- Hilton Head Island · 19 km
- Bluffton · 27 km
- Hardeeville · 33 km
- Wilmington Island · 47 km
- Rincon · 51 km
- Port Wentworth · 51 km
- Garden City · 54 km
Frost dates recorded at BEAUFORT WWTP, 4 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Port Royal, SC — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00380559. Retrieved from https://blissgarden.com/south-carolina/port-royal.