Sitka Airport, AK Frost Dates & Growing Season

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

Last spring frost
Apr 12
~50% chance of frost after
First fall frost
Nov 1
~50% chance of frost before
Growing season
203 days
frost-free stretch
USDA zone
≈ 6a
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Mar 28 Apr 12 Apr 30
First fall frost Nov 21 Nov 1 Oct 13
Hard freeze (28°F), median last Mar 24 · first Nov 22

Computed from NOAA 1991–2020 climate normals at the SITKA AIRPORT 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 Sitka Airport

Computed from Sitka Airport'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 15 – Mar 1 Apr 19 – Apr 26
🫑 Peppers Feb 1 – Feb 15 Apr 26 – May 3
🥬 Lettuce Mar 1 – Mar 15 Mar 15 – Mar 29 Mar 15 – Apr 12
🫛 Peas Mar 1 – Mar 15
🥕 Carrots Mar 22 – Apr 12
🥦 Broccoli Feb 22 – Mar 8 Mar 22 – Apr 5
🥬 Kale Mar 1 – Mar 15 Mar 15 – Mar 29 Mar 15 – Mar 29
🥒 Cucumbers Mar 15 – Mar 22 Apr 19 – Apr 26 Apr 19 – Apr 26
🥒 Zucchini Mar 15 – Mar 22 Apr 19 – Apr 26 Apr 19 – Apr 26
🫘 Green Beans (Bush) Apr 19 – Apr 26
🌽 Sweet Corn Apr 19 – Apr 26
🌿 Basil Mar 1 – Mar 15 Apr 19 – Apr 26 Apr 26 – May 3
🧄 Garlic Fall: Sep 20 – Oct 18

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 Sitka Airport's dates automatically after a lookup.

Reading the season in Sitka Airport

With roughly 203 frost-free days, Sitka Airport 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 1 is late enough that fall planting is a full second season, not an afterthought.

Frequently asked questions

When is the last frost in Sitka Airport, AK?

The average last spring frost in Sitka Airport is around Apr 12, 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 Sitka Airport, AK?

The average first fall frost in Sitka Airport arrives around Nov 1. 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 Sitka Airport?

About 203 frost-free days on average, from Apr 12 to Nov 1. That comfortably fits long-season crops like melons and winter squash, plus spring and fall plantings of cool-season vegetables.

What USDA zone is Sitka Airport 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.