Burlington, IA Frost Dates
Average frost dates, USDA hardiness zone, and growing season length for Burlington, Iowa.
Gardening in Burlington
Southeast Iowa's Mississippi River city has one of the longest growing seasons in the state, moderated by the river corridor.
Zone 5b with 177 frost-free days. The Mississippi River provides valley warmth and fertile bottomland. Southeast Iowa's climate is the mildest in the state.
Burlington's river heritage extends to fertile garden soil in the Mississippi's floodplain. The surrounding farmland provides context for home growing.
What This Means for Burlington Gardeners
The average last spring frost in Burlington is around April 18, and the average first fall frost arrives around October 12. That gives you approximately 177 frost-free days to work with.
A solid, workable season. Most standard vegetable varieties have enough time to mature, though the longest-season crops (like sweet potatoes at 90+ days or large watermelons at 85+ days) need to be started early and chosen carefully. Indoor seed starting isn't optional — it's how you buy the extra weeks that make the difference between a good harvest and a great one.
These dates are based on NOAA 30-year Climate Normal data for the Burlington 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 Burlington
Burlington's 177-day season gives you plenty of time for most vegetables with good planning. Start warm-season crops indoors to maximize your window. Cool-season crops thrive in your spring and fall shoulder seasons. Recommended starting points: tomatoes, peppers, lettuce, carrots, beans, broccoli, garlic, and basil.
See the full Iowa planting guide for all 40 plants: Iowa Planting Calendar. Or enter your zip code for exact planting dates personalized to Burlington.
More About Zone 5B
Burlington is in USDA Hardiness Zone 5B, which means average annual extreme minimum temperatures between -15°F to -10°F. View the full Zone 5B planting guide.
See the complete planting calendar for Iowa: Iowa Planting Calendar.
Other Cities in Iowa
Frequently Asked Questions
These dates are based on NOAA's 30-year Climate Normal data for the Burlington 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 Burlington (urban heat islands, hilltops, low-lying valleys) can also shift your local frost dates by a week or more.
Start warm-season seeds indoors 6-8 weeks before your last frost (April 18) to maximize your 177-day window. Direct sow cold-hardy crops like peas and lettuce 3-4 weeks before last frost. Every week of early indoor starting matters at this season length. Enter your zip code for exact dates.