Last frost date in Riverton, Wyoming
May 12
Average last frost in spring. In an early year (1 in 10) it's over by May 1; in a late year (1 in 10) it comes after May 26.
September 24
Average first frost in fall. 1 year in 10 it comes by September 11.
Source: NOAA U.S. Climate Normals 1991–2020, station Riverton (USC00487760), 0.5 miles from Riverton, elevation 4,955 ft. NOAA National Centers for Environmental Information. These are long-term averages, not a forecast.
| Early year | Average | Late year | |
|---|---|---|---|
| Last frost in spring | May 1 | May 12 | May 26 |
| First frost in fall | Sept 11 | Sept 24 | Oct 7 |
An early or late year is one in 10: 1 year in 10 the frost comes before the early date, and 1 year in 10 after the late date.
Frost-free days in an average year: 132
Planting calendar for Riverton
Fall planting
USDA dates for places whose average first freeze is about September 20 (Riverton: September 24).
- Broccoli plantsMay 1 – June 15 (past for this year)
- Brussels sprouts plantsMay 1 – June 15 (past for this year)
- Cabbage plantsMay 1 – June 15 (past for this year)
- Cantaloupe (muskmelon)May 1 – June 15 (past for this year)
- Cauliflower plantsMay 1 – July 1 (past for this year)
- PotatoesMay 1 – June 15 (past for this year)
- WatermelonMay 1 – June 15 (past for this year)
- Celery and celeriac plantsMay 15 – July 1 (past for this year)
- Chervil and chivesMay 15 – June 15 (past for this year)
- Collards plantsMay 15 – June 15 (past for this year)
- ParsnipsMay 15 – June 15 (past for this year)
- Summer squashMay 15 – July 1 (past for this year)
- Witloof chicoryMay 15 – June 15 (past for this year)
- SalsifyMay 20 – June 20 (past for this year)
- Winter squashMay 20 – June 10 (past for this year)
- BeetsJune 1 – July 1 (past for this year)
- CarrotsJune 1 – July 1 (past for this year)
- Chinese cabbageJune 1 – July 1 (past for this year)
- CucumbersJune 1 – 15 (past for this year)
- DandelionJune 1 – July 1 (past for this year)
- Florence fennelJune 1 – July 1 (past for this year)
- Garden peasJune 1 – July 15 (past for this year)
- Head lettuce plantsJune 1 – July 15 (past for this year)
- KaleJune 1 – July 1 (past for this year)
- KohlrabiJune 1 – July 15 (past for this year)
- Leaf lettuceJune 1 – Aug 1 (past for this year)
- Mustard greensJune 1 – Aug 1 (past for this year)
- OkraJune 1 – 20 (past for this year)
- ParsleyJune 1 – July 1 (past for this year)
- Peppers plantsJune 1 – 20 (past for this year)
- RadishesJune 1 – Aug 15 (past for this year)
- RutabagaJune 1 – July 1 (past for this year)
- Snap beansJune 1 – July 1 (past for this year)
- SorrelJune 1 – July 1 (past for this year)
- SpinachJune 1 – Aug 1 (past for this year)
- Sweet cornJune 1 – July 1 (past for this year)
- Swiss chardJune 1 – July 1 (past for this year)
- TomatoesJune 1 – 20 (past for this year)
- TurnipsJune 1 – July 15 (past for this year)
- Corn saladJune 15 – Aug 1 (past for this year)
- EndiveJune 15 – July 15 (past for this year)
- Upland cressJune 15 – Aug 1 (past for this year)
- Rhubarb plantsSept 15 – Nov 1Now
USDA lists garlic, horseradish, leeks, onion plants, onion seed, onion sets, shallots as generally spring-planted here.
Spring planting
USDA dates for places whose average last freeze is about May 10 (Riverton: May 12).
- Cabbage plantsApr 1 – May 15
- Chervil and chivesApr 1 – May 1
- Chinese cabbageApr 1 – May 15
- Corn saladApr 1 – June 1
- DandelionApr 1 – May 1
- Garden peasApr 1 – May 15
- GarlicApr 1 – May 1
- Onion seedApr 1 – May 1
- PotatoesApr 1 – June 1
- RadishesApr 1 – June 1
- Rhubarb plantsApr 1 – May 1
- SpinachApr 1 – June 15
- TurnipsApr 1 – June 1
- Asparagus plantsApr 10 – 30
- KaleApr 10 – May 1
- KohlrabiApr 10 – May 15
- Onion plants plantsApr 10 – May 1
- Onion setsApr 10 – May 1
- ShallotsApr 10 – May 1
- BeetsApr 15 – June 15
- Broccoli plantsApr 15 – June 1
- Brussels sprouts plantsApr 15 – June 1
- Cauliflower plantsApr 15 – May 15
- Collards plantsApr 15 – June 1
- EndiveApr 15 – May 15
- Florence fennelApr 15 – May 15
- Head lettuce plantsApr 15 – May 15
- Horseradish plantsApr 15 – May 15
- Leaf lettuceApr 15 – June 15
- LeeksApr 15 – May 15
- Mustard greensApr 15 – June 1
- ParsleyApr 15 – May 15
- ParsnipsApr 15 – May 15
- SalsifyApr 15 – June 1
- SorrelApr 15 – June 1
- CarrotsApr 20 – June 15
- Celery and celeriac plantsApr 20 – June 15
- Swiss chardApr 20 – June 15
- Upland cressApr 20 – May 20
- RutabagaMay 1 – June 1
- New Zealand spinachMay 10 – June 15
- Snap beansMay 10 – June 30
- Summer squashMay 10 – June 10
- Sweet cornMay 10 – June 1
- TomatoesMay 15 – June 10
- CucumbersMay 20 – June 15
- Eggplant plantsMay 20 – June 15
- OkraMay 20 – June 10
- Peppers plantsMay 20 – June 10
- Lima beansMay 25 – June 15
- SoybeansMay 25 – June 10
- Cantaloupe (muskmelon)June 1 – 15
- WatermelonJune 1 – 15
- Witloof chicoryJune 1 – 20
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), “Suburban and Farm Vegetable Gardens,” tables 4 and 5 (earliest safe spring and latest safe fall dates), applied to this place's NOAA frost dates. “Plants” means setting out transplants, not sowing seed. How we match the table.
Nearby in Wyoming
- Casper 105 mi · last frost May 10
- Rock Springs 108 mi · last frost May 24
- Cody 109 mi · last frost May 12
- Green River 118 mi · last frost May 24
- Jackson 124 mi · last frost June 20