USDA zone 9a in Nevada
USDA plant hardiness zone 9a covers 11 locations across Nevada (average annual extreme minimum 20 to 25 °F): Cal-Nev-Ari, NV, Cal-Nev-Ari, NV, Goodsprings, NV, Henderson, NV, Las Vegas, NV, Las Vegas, NV, and 5 more. Average last spring frost across this group ranges January 20 (Las Vegas) to March 22 (Las Vegas), and growing seasons run 229–333 days (Las Vegas to Las Vegas) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Nevada location's own frost dates; the printable planting calendar uses Moapa Valley, this group's median-season location.
- USDA zone
- 9a20 to 25 °F
- Last frost range
- Jan 20–Mar 22avg, 32°F
- First frost range
- Nov 7–Dec 15avg, 32°F
- Growing season range
- 229–333days
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) |
|---|---|---|---|---|---|
| Cal-Nev-Ari | — | Mitchell Caverns | Mar 6 | Dec 8 | 272 |
| Cal-Nev-Ari | — | Searchlight | Mar 7 | Nov 29 | 266 |
| Goodsprings | — | Goodsprings | Mar 17 | Nov 20 | 245 |
| Henderson | Enterprise, Spring Valley, Goodsprings | Las Vegas Wfo | Feb 4 | Dec 5 | 302 |
| Las Vegas | Spring Valley | Las Vegas Mccarran Ap | Jan 20 | Dec 15 | 333 |
| Las Vegas | — | Las Vegas Air Terminal | Jan 24 | Dec 10 | 323 |
| Las Vegas | Summerlin South | Red Rock Canyon - Spg Mt Rch S | Mar 13 | Nov 15 | 244 |
| Las Vegas | — | Desert Nwr | Mar 22 | Nov 7 | 229 |
| Mesquite | — | Bunkerville | Mar 16 | Nov 13 | 238 |
| Moapa Valley * | Moapa, Bunkerville | Overton | Feb 26 | Nov 22 | 268 |
| North Las Vegas | — | N Las Vegas | Feb 1 | Dec 8 | 311 |
* Moapa Valley 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 (Moapa Valley, representative)
Computed from Moapa Valley's average frost dates — the median-season location in this Nevadazone 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 1 – Jan 15 | Mar 5 – Mar 12 | May 4 – May 24 | — | matures comfortably |
| Pepper | Very tender | Jan 1 | Mar 12 – Mar 19 | May 11 – Jun 10 | — | matures comfortably |
| Cucumber | Tender | Jan 29 – Feb 5 | Mar 5 – Mar 12 | Apr 24 – May 14 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Mar 5 – Mar 12 | Apr 19 – May 4 | — | matures comfortably |
| Bush bean | Tender | — | Mar 5 – Mar 12 | Apr 24 – May 4 | Sep 23 – Oct 3 | matures comfortably |
| Sweet corn | Tender | — | Feb 26 – Mar 12 | Apr 27 – May 27 | — | matures comfortably |
| Basil | Very tender | Jan 15 – Jan 29 | Mar 5 – Mar 12 | Apr 4 – Apr 19 | — | matures comfortably |
| Lettuce | Half-hardy | Jan 15 – Jan 29 | Jan 29 – Feb 12 | Mar 15 – Mar 30 | Sep 9 – Sep 24 | matures comfortably |
| Pea | Hardy | — | Jan 15 – Jan 29 | Mar 11 – Mar 26 | Aug 30 – Sep 14 | matures comfortably |
| Spinach | Hardy | — | Jan 15 – Jan 29 | Feb 24 – Mar 6 | Sep 19 – Sep 29 | matures comfortably |
| Carrot | Half-hardy | — | Feb 5 – Feb 12 | Apr 6 – Apr 26 | Aug 20 – Sep 9 | matures comfortably |
| Broccoli | Half-hardy | Jan 1 – Jan 15 | Jan 29 – Feb 12 | Mar 25 – Apr 14 | Aug 25 – Sep 14 | matures comfortably |
Which crops fit this growing season
Using Moapa Valley's own 268-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 (Moapa Valley)
From NOAA's 1991–2020 Climate Normals at station USC00265846. 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 15 | Apr 11 | Nov 12 | Nov 24 | 238 |
| 32°F (freeze) | Feb 26 | Mar 16 | Nov 22 | Dec 6 | 268 |
| 28°F | Feb 5 | Feb 28 | Dec 2 | Dec 23 | 299 |
| 24°F | Jan 15 | Feb 10 | Dec 16 | Jan 9 | 336 |
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 11 locations is 6,175; Moapa Valley's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 7,159 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 10,517 | cool-season crops (brassicas, greens) |
Hardiness zone 9a in Nevada
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. Nevada spans 10 hardiness zones in this dataset — see all Nevada locations for the full range, including zones5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9b.
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 Nevada?
- Zone 9a means an average annual extreme minimum winter temperature of 20 to 25 °F — the standard USDA measure of which perennials survive winter. 11 locations in Nevada fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Nevada's zone 9a is the growing season longest?
- Las Vegas runs the longest season on this page at about 333 days; Las Vegas is shortest at about 229 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 Nevada's zone 9a?
- Using Moapa Valley's frost dates (this page's median-season location): start seeds indoors about Jan 1 – Jan 15, then transplant outside about Mar 5 – Mar 12. 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 Nevada'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 11 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.