When to plant in Twin Falls, ID
USDA Zone 7aEverything below — frost dates, hardiness zone, and what to plant when in Twin Falls, Idaho — is derived from the closest NOAA station with complete climate normals.
In zone 7a, Twin Falls supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.
The average first fall frost in Twin Falls is now 6 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
TWIN FALLS-KMVT · 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 Twin Falls’s own odds, recorded at TWIN FALLS-KMVT.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Jun 2 | May 14 | May 1 | Sep 12 | Sep 28 | Oct 12 |
| 32°F | May 14 | Apr 30 | Apr 17 | Sep 24 | Oct 9 | Oct 24 |
| 28°F | Apr 30 | Apr 17 | Mar 30 | Oct 7 | Oct 23 | Nov 5 |
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 Twin Falls, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 10 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.
Twin Falls planting FAQ
When is the last spring frost in Twin Falls, ID?
On average, the last spring frost in Twin Falls is around April 30 (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 Twin Falls, ID?
In Twin Falls, the first 32°F freeze of fall lands around October 9 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Twin Falls in?
Twin Falls is in USDA hardiness zone 7a. In zone 7a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Twin Falls?
Twin Falls has about 162 frost-free days — a moderate growing season — between the average last spring frost (April 30) and first fall frost (October 9).
When should I plant tomatoes in Twin Falls?
For Twin Falls, sow tomatoes indoors about March 5–March 19 and move the seedlings out around May 7, after the last spring frost.
Never miss a window in Twin Falls
An email when it’s time to start seeds, transplant, and sow — timed to Twin Falls’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Jerome · 18 km
- Burley · 55 km
- Mountain Home · 119 km
- Pocatello · 167 km
- Chubbuck · 168 km
- Boise City · 184 km
- Blackfoot · 186 km
- Kuna · 191 km
Frost dates recorded at TWIN FALLS-KMVT, 2 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 Twin Falls, ID — Frost Dates & Zone 7a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00109293. Retrieved from https://blissgarden.com/idaho/twin-falls.