NEW Boston Dam 17, IL Frost Dates & Growing Season

The two dates every NEW Boston Dam 17 garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Apr 14
~50% chance of frost after
First fall frost
Oct 24
~50% chance of frost before
Growing season
193 days
frost-free stretch
USDA zone
≈ 6a
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Apr 1 Apr 14 May 2
First fall frost Nov 4 Oct 24 Oct 9
Hard freeze (28°F), median last Apr 5 · first Nov 1

Computed from NOAA 1991–2020 climate normals at the NEW BOSTON DAM 17 station. "Safe" means frost past that date happens only about one year in ten. Your exact garden can still run days either way with elevation and terrain — check your own ZIP with the frost date lookup.

Planting windows for NEW Boston Dam 17

Computed from NEW Boston Dam 17's own frost dates. Click any crop for the full zone-6 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Feb 17 – Mar 3 Apr 21 – Apr 28
🫑 Peppers Feb 3 – Feb 17 Apr 28 – May 5
🥬 Lettuce Mar 3 – Mar 17 Mar 17 – Mar 31 Mar 17 – Apr 14
🫛 Peas Mar 3 – Mar 17
🥕 Carrots Mar 24 – Apr 14
🥦 Broccoli Feb 24 – Mar 10 Mar 24 – Apr 7
🥬 Kale Mar 3 – Mar 17 Mar 17 – Mar 31 Mar 17 – Mar 31
🥒 Cucumbers Mar 17 – Mar 24 Apr 21 – Apr 28 Apr 21 – Apr 28
🥒 Zucchini Mar 17 – Mar 24 Apr 21 – Apr 28 Apr 21 – Apr 28
🫘 Green Beans (Bush) Apr 21 – Apr 28
🌽 Sweet Corn Apr 21 – Apr 28
🌿 Basil Mar 3 – Mar 17 Apr 21 – Apr 28 Apr 28 – May 5
🧄 Garlic Fall: Sep 12 – Oct 10

Want this for all 50 crops, or as a printable seed-shelf schedule? Use the planting calendar and the seed starting scheduler — both can use NEW Boston Dam 17's dates automatically after a lookup.

Reading the season in NEW Boston Dam 17

Roughly 193 frost-free days gives NEW Boston Dam 17 gardeners room for nearly every common vegetable. Warm-season crops go out after Apr 14; a fall garden sown in late summer matures comfortably before the Oct 24 frost.

Frequently asked questions

When is the last frost in NEW Boston Dam 17, IL?

The average last spring frost in NEW Boston Dam 17 is around Apr 14, based on 1991–2020 climate normals. That's a median — about half of years see a later frost, so tender crops are safest going out a week or two after this date.

When is the first frost in NEW Boston Dam 17, IL?

The average first fall frost in NEW Boston Dam 17 arrives around Oct 24. Crops still in the garden need to mature before then, and frost-tender plants need harvesting or protection as the date approaches.

How long is the growing season in NEW Boston Dam 17?

About 193 frost-free days on average, from Apr 14 to Oct 24. That fits nearly all common vegetables, though the longest-season melons and sweet potatoes benefit from transplants.

What USDA zone is NEW Boston Dam 17 in?

USDA zone 6a on the 2023 Plant Hardiness Zone Map. Note that zones describe winter cold, not frost timing — these frost dates are the numbers to plan plantings around.