Boulder City, NV planting zone & frost dates
Boulder City is in USDA hardiness zone 9b. The last spring frost usually comes around January 21 and the first fall frost around December 17, for a growing season of about 328 days.
Planting calendar for Boulder City
Dates are counted from the average last spring frost (January 21) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Nov 26 – Dec 10 Transplant outdoors: Jan 28 – Feb 4 |
| Peppers | Start seeds indoors: Nov 12 – Nov 26 Transplant outdoors: Feb 4 – Feb 11 |
| Eggplant | Start seeds indoors: Nov 12 – Nov 26 Transplant outdoors: Feb 4 – Feb 11 |
| Broccoli | Start seeds indoors: Nov 12 – Nov 26 Transplant outdoors: Dec 24 – Jan 7 |
| Cabbage | Start seeds indoors: Nov 12 – Nov 26 Transplant outdoors: Dec 24 – Jan 7 |
| Onions (sets) | Plant outdoors: Dec 24 – Jan 7 |
| Peas | Sow outdoors: Dec 10 – Dec 24 |
| Spinach | Sow outdoors: Dec 10 – Dec 24 |
| Lettuce | Sow outdoors: Dec 24 – Jan 7 |
| Carrots | Sow outdoors: Dec 24 – Jan 7 |
| Potatoes | Plant outdoors: Dec 24 – Jan 7 |
| Beans | Sow outdoors: Jan 28 – Feb 4 |
| Sweet corn | Sow outdoors: Jan 28 – Feb 4 |
| Cucumbers | Sow outdoors: Jan 28 – Feb 4 |
| Squash & zucchini | Sow outdoors: Jan 28 – Feb 4 |
| Basil | Start seeds indoors: Dec 10 – Dec 24 Transplant outdoors: Jan 28 – Feb 4 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Oct 22 (8 weeks before the average first fall frost on Dec 17).
Useful for zone 9b gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
- Shade cloth — for hot summers
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Dec 29 | Jan 21 | Mar 5 |
| First 32°F frost in fall is before | Jan 3 | Dec 17 | Dec 2 |
How to read it: in spring there is a 10% chance of a frost after March 5, so that is a safe date for tender plants. In fall there is a 10% chance of frost before December 2. A hard freeze (28°F) usually ends around January 10.
Hardiness zone by ZIP code in Boulder City
- 89005 zone 9b
- 89006 zone 9b
Nearby cities
- Henderson zone 9b, last frost Jan 20
- Whitney zone 9b, last frost Jan 20
- Winchester zone 9b, last frost Jan 20
- Sunrise Manor zone 9b, last frost Feb 1
- Paradise zone 9b, last frost Jan 20
- North Las Vegas zone 9b, last frost Feb 1
- Las Vegas zone 9b, last frost Jan 24
- Enterprise zone 9a, last frost Feb 4
Questions
What growing zone is Boulder City, NV?
Boulder City is in USDA Plant Hardiness Zone 9b (average extreme winter low 25°F to 30°F), according to the USDA 2023 map.
When is the last frost in Boulder City?
The average last spring frost (32°F) in Boulder City is January 21. There is still a 10% chance of frost until March 5.
When can I plant tomatoes in Boulder City?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Jan 28 – Feb 4. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Alan Bible Visitor Ctr, NV (USC00260125), 4.8 km (3.0 mi) from the city center, elevation 500 m, based on 13 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.