Riverside 7 SSW, OR Frost Dates & Growing Season

The two dates every Riverside 7 SSW garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Jun 7
~50% chance of frost after
First fall frost
Sep 6
~50% chance of frost before
Growing season
91 days
frost-free stretch
USDA zone
≈ 6b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost May 21 Jun 7 Jun 28
First fall frost Sep 22 Sep 6 Aug 22
Hard freeze (28°F), median last May 20 · first Sep 19

Computed from NOAA 1991–2020 climate normals at the RIVERSIDE 7 SSW 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 Riverside 7 SSW

Computed from Riverside 7 SSW'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 Apr 12 – Apr 26 Jun 14 – Jun 21
🫑 Peppers Mar 29 – Apr 12 Jun 21 – Jun 28
🥬 Lettuce Apr 26 – May 10 May 10 – May 24 May 10 – Jun 7
🫛 Peas Apr 26 – May 10
🥕 Carrots May 17 – Jun 7
🥦 Broccoli Apr 19 – May 3 May 17 – May 31
🥬 Kale Apr 26 – May 10 May 10 – May 24 May 10 – May 24
🥒 Cucumbers May 10 – May 17 Jun 14 – Jun 21 Jun 14 – Jun 21
🥒 Zucchini May 10 – May 17 Jun 14 – Jun 21 Jun 14 – Jun 21
🫘 Green Beans (Bush) Jun 14 – Jun 21
🌽 Sweet Corn Jun 14 – Jun 21
🌿 Basil Apr 26 – May 10 Jun 14 – Jun 21 Jun 21 – Jun 28
🧄 Garlic Fall: Jul 26 – Aug 23

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 Riverside 7 SSW's dates automatically after a lookup.

Reading the season in Riverside 7 SSW

At about 91 frost-free days, Riverside 7 SSW rewards efficiency: start warm-season crops indoors, favor short-season varieties, and lean on cold-tolerant crops — peas, kale, roots — that shrug off the shoulder-season frosts on either end.

Frequently asked questions

When is the last frost in Riverside 7 SSW, OR?

The average last spring frost in Riverside 7 SSW is around Jun 7, 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 Riverside 7 SSW, OR?

The average first fall frost in Riverside 7 SSW arrives around Sep 6. 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 Riverside 7 SSW?

About 91 frost-free days on average, from Jun 7 to Sep 6. That favors short-season varieties and transplants for warm-season crops, with cool-season vegetables doing the heavy lifting in spring and fall.

What USDA zone is Riverside 7 SSW 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.