USDA zone 9a in Mississippi
USDA plant hardiness zone 9a covers 10 locations across Mississippi (average annual extreme minimum 20 to 25 °F): Centreville, MS, Crosby, MS, Gulfport, MS, Gulfport, MS, Kiln, MS, Pearlington, MS, and 4 more. Average last spring frost across this group ranges February 12 (Gulfport) to March 16 (Crosby), and growing seasons run 237–301 days (Crosby to Gulfport) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Mississippi location's own frost dates; the printable planting calendar uses Pearlington, this group's median-season location.
- USDA zone
- 9a20 to 25 °F
- Last frost range
- Feb 12–Mar 16avg, 32°F
- First frost range
- Nov 9–Dec 14avg, 32°F
- Growing season range
- 237–301days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Centreville | Woodville | Woodville 4 Ese | Mar 11 | Nov 17 | 251 |
| Crosby | Ferriday | Natchez | Mar 16 | Nov 9 | 237 |
| Gulfport | Long Beach, Lyman | Gulfport - Biloxi Ap | Feb 23 | Dec 3 | 287 |
| Gulfport | Biloxi, Ocean Springs | Biloxi | Feb 12 | Dec 14 | 301 |
| Kiln | Diamondhead, Waveland, DeLisle | Waveland | Feb 21 | Dec 3 | 287 |
| Pearlington * | — | Bay St Louis Nasa | Mar 6 | Nov 19 | 262 |
| Picayune | — | Picayune | Mar 9 | Nov 18 | 255 |
| Poplarville | Hide-A-Way Lake | Poplarville Exp Stn | Mar 10 | Nov 21 | 257 |
| Saucier | — | Saucier Exp Forest | Mar 7 | Nov 22 | 260 |
| Vancleave | Gautier, Moss Point, Pascagoula, Big Point | Pascagoula Lott Intl Ap | Mar 1 | Nov 24 | 269 |
* Pearlington is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Pearlington, representative)
Computed from Pearlington's average frost dates — the median-season location in this Mississippizone 9a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Jan 9 – Jan 23 | Mar 13 – Mar 20 | May 12 – Jun 1 | — | matures comfortably |
| Pepper | Very tender | Jan 1 – Jan 9 | Mar 20 – Mar 27 | May 19 – Jun 18 | — | matures comfortably |
| Cucumber | Tender | Feb 6 – Feb 13 | Mar 13 – Mar 20 | May 2 – May 22 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Mar 13 – Mar 20 | Apr 27 – May 12 | — | matures comfortably |
| Bush bean | Tender | — | Mar 13 – Mar 20 | May 2 – May 12 | Sep 20 – Sep 30 | matures comfortably |
| Sweet corn | Tender | — | Mar 6 – Mar 20 | May 5 – Jun 4 | — | matures comfortably |
| Basil | Very tender | Jan 23 – Feb 6 | Mar 13 – Mar 20 | Apr 12 – Apr 27 | — | matures comfortably |
| Lettuce | Half-hardy | Jan 23 – Feb 6 | Feb 6 – Feb 20 | Mar 23 – Apr 7 | Sep 6 – Sep 21 | matures comfortably |
| Pea | Hardy | — | Jan 23 – Feb 6 | Mar 19 – Apr 3 | Aug 27 – Sep 11 | matures comfortably |
| Spinach | Hardy | — | Jan 23 – Feb 6 | Mar 4 – Mar 14 | Sep 16 – Sep 26 | matures comfortably |
| Carrot | Half-hardy | — | Feb 13 – Feb 20 | Apr 14 – May 4 | Aug 17 – Sep 6 | matures comfortably |
| Broccoli | Half-hardy | Jan 9 – Jan 23 | Feb 6 – Feb 20 | Apr 2 – Apr 22 | Aug 22 – Sep 11 | matures comfortably |
Which crops fit this growing season
Using Pearlington's own 262-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Pearlington)
From NOAA's 1991–2020 Climate Normals at station USC00220521. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | Mar 22 | Apr 11 | Nov 7 | Nov 27 | 235 |
| 32°F (freeze) | Mar 6 | Mar 27 | Nov 19 | Dec 13 | 262 |
| 28°F | Feb 16 | Mar 16 | Dec 4 | Jan 16 | 296 |
| 24°F | Jan 30 | Mar 5 | Dec 31 | Feb 6 | 334 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 10 locations is 6,398; Pearlington's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 6,027 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 9,395 | cool-season crops (brassicas, greens) |
Hardiness zone 9a in Mississippi
Zone 9a means an average annual extreme minimum winter temperature of about 20 to 25 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Mississippi spans 4 hardiness zones in this dataset — see all Mississippi locations for the full range, including zones7b, 8a, 8b.
Explore zone 9a in other states at zone 9a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 9a mean in Mississippi?
- Zone 9a means an average annual extreme minimum winter temperature of 20 to 25 °F — the standard USDA measure of which perennials survive winter. 10 locations in Mississippi fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Mississippi's zone 9a is the growing season longest?
- Gulfport runs the longest season on this page at about 301 days; Crosby is shortest at about 237 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Mississippi's zone 9a?
- Using Pearlington's frost dates (this page's median-season location): start seeds indoors about Jan 9 – Jan 23, then transplant outside about Mar 13 – Mar 20. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Mississippi's zone 9a have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 10 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.