When to plant in St. George, UT
USDA Zone 8bEverything below — frost dates, hardiness zone, and what to plant when in St. George, Utah — is derived from the closest NOAA station with complete climate normals.
St. George enjoys a long ~241-day frost-free season — you can succession-sow, fit in a second crop, and grow long-season heat-lovers with room to spare. In zone 8b, St. George supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.
The average last spring frost in St. George is now 7 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
ST GEORGE · 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 St. George’s own odds, recorded at ST GEORGE.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 21 | Apr 3 | Mar 17 | Oct 19 | Nov 1 | Nov 12 |
| 32°F | Apr 6 | Mar 14 | Feb 27 | Oct 27 | Nov 10 | Nov 22 |
| 28°F | Mar 17 | Feb 27 | Feb 7 | Nov 7 | Nov 20 | Dec 3 |
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 St. George, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 32 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.
St. George planting FAQ
When is the last spring frost in St. George, UT?
On average, the last spring frost in St. George is around March 14 (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 St. George, UT?
Expect St. George's first fall frost near November 10 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is St. George in?
St. George is in USDA hardiness zone 8b. In zone 8b, winters are mild — many tender perennials overwinter here.
How long is the growing season in St. George?
St. George has about 241 frost-free days — a long growing season — between the average last spring frost (March 14) and first fall frost (November 10).
When should I plant tomatoes in St. George?
For St. George, sow tomatoes indoors about January 17–January 31 and move the seedlings out around March 21, after the last spring frost.
Never miss a window in St. George
An email when it’s time to start seeds, transplant, and sow — timed to St. George’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Washington · 10 km
- Hurricane · 21 km
- Mesquite · 57 km
- Cedar City · 80 km
- North Las Vegas · 161 km
- Sunrise Manor · 165 km
- Whitney · 170 km
- Winchester · 174 km
Frost dates recorded at ST GEORGE, 5 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 St. George, UT — Frost Dates & Zone 8b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00427516. Retrieved from https://blissgarden.com/utah/st-george.