Mt Vernon 3 WNW, WA Frost Dates & Growing Season

The two dates every Mt Vernon 3 WNW garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Mar 24
~50% chance of frost after
First fall frost
Nov 3
~50% chance of frost before
Growing season
224 days
frost-free stretch
USDA zone
≈ 9a
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Mar 3 Mar 24 Apr 14
First fall frost Nov 25 Nov 3 Oct 12
Hard freeze (28°F), median last Feb 27 · first Nov 25

Computed from NOAA 1991–2020 climate normals at the MT VERNON 3 WNW 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 Mt Vernon 3 WNW

Computed from Mt Vernon 3 WNW's own frost dates. Click any crop for the full zone-9 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Jan 27 – Feb 10 Mar 31 – Apr 7
🫑 Peppers Jan 13 – Jan 27 Apr 7 – Apr 14
🥬 Lettuce Feb 10 – Feb 24 Feb 24 – Mar 10 Feb 24 – Mar 24
🫛 Peas Feb 10 – Feb 24
🥕 Carrots Mar 3 – Mar 24
🥦 Broccoli Feb 3 – Feb 17 Mar 3 – Mar 17
🥬 Kale Feb 10 – Feb 24 Feb 24 – Mar 10 Feb 24 – Mar 10
🥒 Cucumbers Feb 24 – Mar 3 Mar 31 – Apr 7 Mar 31 – Apr 7
🥒 Zucchini Feb 24 – Mar 3 Mar 31 – Apr 7 Mar 31 – Apr 7
🫘 Green Beans (Bush) Mar 31 – Apr 7
🌽 Sweet Corn Mar 31 – Apr 7
🌿 Basil Feb 10 – Feb 24 Mar 31 – Apr 7 Apr 7 – Apr 14
🧄 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 Mt Vernon 3 WNW's dates automatically after a lookup.

Reading the season in Mt Vernon 3 WNW

With roughly 224 frost-free days, Mt Vernon 3 WNW 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 Mt Vernon 3 WNW, WA?

The average last spring frost in Mt Vernon 3 WNW is around Mar 24, 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 Mt Vernon 3 WNW, WA?

The average first fall frost in Mt Vernon 3 WNW 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 Mt Vernon 3 WNW?

About 224 frost-free days on average, from Mar 24 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 Mt Vernon 3 WNW in?

USDA zone 9a 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.