When to plant in Green River, WY
USDA Zone 5aGreen River, Wyoming frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
In zone 5a, Green River gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
Frost probability
GREEN RVR · 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 Green River’s own odds, recorded at GREEN RVR.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Jun 21 | Jun 7 | May 22 | Sep 1 | Sep 13 | Sep 25 |
| 32°F | Jun 10 | May 24 | May 7 | Sep 7 | Sep 22 | Oct 6 |
| 28°F | May 28 | May 9 | Apr 25 | Sep 18 | Oct 3 | Oct 18 |
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 Green River, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 31 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.
Green River planting FAQ
When is the last spring frost in Green River, WY?
Plan for the last spring frost in Green River around May 24 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Green River, WY?
In Green River, the first 32°F freeze of fall lands around September 22 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Green River in?
Green River is in USDA hardiness zone 5a. In zone 5a, winters are cold — pick cold-hardy varieties and protect tender crops.
How long is the growing season in Green River?
Green River has about 121 frost-free days — a short growing season — between the average last spring frost (May 24) and first fall frost (September 22).
When should I plant tomatoes in Green River?
For Green River, sow tomatoes indoors about March 29–April 12 and move the seedlings out around May 31, after the last spring frost.
Never miss a window in Green River
An email when it’s time to start seeds, transplant, and sow — timed to Green River’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Rock Springs · 23 km
- Vernal · 118 km
- Evanston · 128 km
- Riverton · 191 km
- Heber · 194 km
- North Logan · 196 km
- Hyrum · 198 km
- Logan · 199 km
Frost dates recorded at GREEN RVR, 0 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 Green River, WY — Frost Dates & Zone 5a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00484065. Retrieved from https://blissgarden.com/wyoming/green-river.