Coeur d'Alene, ID Frost Dates
Average frost dates, USDA hardiness zone, and growing season length for Coeur d'Alene, Idaho.
Gardening in Coeur d'Alene
North Idaho's lake city has a Pacific Northwest climate influence that sets it apart from the rest of the state. Lake Coeur d'Alene moderates temperatures beautifully.
Zone 6a with 146 frost-free days. The lake influence extends the fall season and moderates winter cold. The surrounding evergreen forests create a different microclimate than the open prairie to the south.
The Coeur d'Alene lakefront community combines outdoor recreation with food growing. The Wednesday Farmers Market downtown serves a growing food-conscious population.
What This Means for Coeur d'Alene Gardeners
The average last spring frost in Coeur d'Alene is around May 5, and the average first fall frost arrives around September 28. That gives you approximately 146 frost-free days to work with.
At 146 days, you're working with a compressed but productive window. Choose varieties by their days-to-maturity number — anything under 75 days is safe, 75-90 requires indoor starting, and 90+ is a calculated risk. The tradeoff: your cool, moderate summers are excellent for crops that heat-zone gardeners struggle with. Your lettuce doesn't bolt in June. Your peas produce for weeks longer. Cool-season crops are your superpower.
These dates are based on NOAA 30-year Climate Normal data for the Coeur d'Alene 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 Coeur d'Alene
With 146 frost-free days, Coeur d'Alene 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 Idaho planting guide for all 40 plants: Idaho Planting Calendar. Or enter your zip code for exact planting dates personalized to Coeur d'Alene.
More About Zone 6A
Coeur d'Alene is in USDA Hardiness Zone 6A, which means average annual extreme minimum temperatures between -10°F to -5°F. View the full Zone 6A planting guide.
See the complete planting calendar for Idaho: Idaho Planting Calendar.
Other Cities in Idaho
Frequently Asked Questions
These dates are based on NOAA's 30-year Climate Normal data for the Coeur d'Alene 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 Coeur d'Alene (urban heat islands, hilltops, low-lying valleys) can also shift your local frost dates by a week or more.
Start everything possible indoors — your 146-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 (May 5). Choose short-season varieties for warm crops. Enter your zip code for exact dates.