When to plant in Bay St. Louis, MS
USDA Zone 9aEverything below — frost dates, hardiness zone, and what to plant when in Bay St. Louis, Mississippi — is derived from the closest NOAA station with complete climate normals.
A generous ~285-day season lets Bay St. Louis gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. In zone 9a, frost is a minor factor for Bay St. Louis — most perennials thrive, and annual vegetables can go out early and stay late.
The average last spring frost in Bay St. Louis is now 5 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
WAVELAND · 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 Bay St. Louis’s own odds, recorded at WAVELAND.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 3 | Mar 10 | Feb 15 | Nov 2 | Nov 19 | Dec 9 |
| 32°F | Mar 18 | Feb 21 | Jan 25 | Nov 13 | Dec 3 | Jan 2 |
| 28°F | Mar 6 | Feb 2 | Dec 31 | Nov 27 | Dec 25 | Jan 25 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Bay St. Louis, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 24 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.
Bay St. Louis planting FAQ
When is the last spring frost in Bay St. Louis, MS?
Plan for the last spring frost in Bay St. Louis around February 21 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Bay St. Louis, MS?
The first fall frost in Bay St. Louis typically arrives around December 3 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Bay St. Louis in?
Bay St. Louis is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Bay St. Louis?
Bay St. Louis has about 285 frost-free days — a long growing season — between the average last spring frost (February 21) and first fall frost (December 3).
When should I plant tomatoes in Bay St. Louis?
For Bay St. Louis, sow tomatoes indoors about December 27–January 10 and move the seedlings out around February 28, after the last spring frost.
Never miss a window in Bay St. Louis
An email when it’s time to start seeds, transplant, and sow — timed to Bay St. Louis’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Long Beach · 19 km
- Gulfport · 30 km
- Picayune · 38 km
- Slidell · 41 km
- Biloxi · 42 km
- D'Iberville · 46 km
- Ocean Springs · 55 km
- New Orleans · 63 km
Frost dates recorded at WAVELAND, 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 Bay St. Louis, MS — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00229426. Retrieved from https://blissgarden.com/mississippi/bay-st-louis.