Jackson, WY Frost Dates
Average frost dates, USDA hardiness zone, and growing season length for Jackson, Wyoming.
Gardening in Jackson
Jackson Hole's world-famous resort community sits at 6,200 feet in a mountain valley. The growing season of 96 days is among the shortest in America — and gardeners here do it anyway.
Zone 4a with only 96 frost-free days. The Teton Valley's cold-air drainage creates the shortest growing season of any city in this guide. High tunnels and cold frames are essential infrastructure, not optional accessories.
Jackson's wealth and food consciousness create a small but dedicated growing community. When your season is 96 days, every plant is a triumph.
What This Means for Jackson Gardeners
The average last spring frost in Jackson is around June 1, and the average first fall frost arrives around September 5. That gives you approximately 96 frost-free days to work with.
96 frost-free days means every warm day counts. Focus on cold-hardy crops that thrive in your moderate temperatures: kale, lettuce, peas, radishes, potatoes, and root vegetables. For warm-season crops, choose only the shortest-season varieties (sub-65-day tomatoes, 55-day beans) and start everything indoors. Season extension — row covers, cold frames, plastic mulch — isn't a luxury here, it's essential infrastructure.
These dates are based on NOAA 30-year Climate Normal data for the Jackson area. Your actual frost dates could shift 2-3 weeks in either direction in any given year. Learn more about our data sources.
What to Grow in Jackson
With 96 frost-free days, Jackson gardeners need to plan strategically — start warm-season crops indoors and choose short-season varieties. Cool-season crops are your strength, thriving in the moderate temperatures that define your growing window. Recommended starting points: kale, lettuce, peas, carrots, potatoes, radishes, garlic, and short-season tomatoes.
See the full Wyoming planting guide for all 40 plants: Wyoming Planting Calendar. Or enter your zip code for exact planting dates personalized to Jackson.
More About Zone 4A
Jackson is in USDA Hardiness Zone 4A, which means average annual extreme minimum temperatures between -30°F to -25°F. View the full Zone 4A planting guide.
See the complete planting calendar for Wyoming: Wyoming Planting Calendar.
Other Cities in Wyoming
Frequently Asked Questions
These dates are based on NOAA's 30-year Climate Normal data for the Jackson area. They represent historical averages, not predictions. In any given year, the actual last frost could be 2-3 weeks earlier or later. Microclimates within Jackson (urban heat islands, hilltops, low-lying valleys) can also shift your local frost dates by a week or more.
Start everything possible indoors — your 96-day season doesn't leave room for a slow start. Direct sow only the fastest, hardiest crops (radishes, lettuce, peas) 3-4 weeks before last frost (June 1). Choose short-season varieties for warm crops. Enter your zip code for exact dates.