W Harwich, MA Frost Dates & Growing Season

The two dates every W Harwich garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Apr 13
~50% chance of frost after
First fall frost
Nov 3
~50% chance of frost before
Growing season
204 days
frost-free stretch
USDA zone
≈ 6b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Apr 2 Apr 13 Apr 26
First fall frost Nov 18 Nov 3 Oct 22
Hard freeze (28°F), median last Apr 1 · first Nov 17

Computed from NOAA 1991–2020 climate normals at the W HARWICH 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 W Harwich

Computed from W Harwich'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 16 – Mar 2 Apr 20 – Apr 27
🫑 Peppers Feb 2 – Feb 16 Apr 27 – May 4
🥬 Lettuce Mar 2 – Mar 16 Mar 16 – Mar 30 Mar 16 – Apr 13
🫛 Peas Mar 2 – Mar 16
🥕 Carrots Mar 23 – Apr 13
🥦 Broccoli Feb 23 – Mar 9 Mar 23 – Apr 6
🥬 Kale Mar 2 – Mar 16 Mar 16 – Mar 30 Mar 16 – Mar 30
🥒 Cucumbers Mar 16 – Mar 23 Apr 20 – Apr 27 Apr 20 – Apr 27
🥒 Zucchini Mar 16 – Mar 23 Apr 20 – Apr 27 Apr 20 – Apr 27
🫘 Green Beans (Bush) Apr 20 – Apr 27
🌽 Sweet Corn Apr 20 – Apr 27
🌿 Basil Mar 2 – Mar 16 Apr 20 – Apr 27 Apr 27 – May 4
🧄 Garlic Fall: Sep 22 – Oct 20

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 W Harwich's dates automatically after a lookup.

Reading the season in W Harwich

With roughly 204 frost-free days, W Harwich gardens fit long-season crops — melons, winter squash, sweet potatoes — with room left for spring and fall rounds of greens and roots. The first frost around Nov 3 is late enough that fall planting is a full second season, not an afterthought.

Frequently asked questions

When is the last frost in W Harwich, MA?

The average last spring frost in W Harwich is around Apr 13, 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 W Harwich, MA?

The average first fall frost in W Harwich arrives around Nov 3. 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 W Harwich?

About 204 frost-free days on average, from Apr 13 to Nov 3. That comfortably fits long-season crops like melons and winter squash, plus spring and fall plantings of cool-season vegetables.

What USDA zone is W Harwich in?

USDA zone 6b 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.