Riverside Fire Stn 3, CA Frost Dates & Growing Season

The two dates every Riverside Fire Stn 3 garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
Jan 9
~50% chance of frost after
First fall frost
Dec 25
~50% chance of frost before
Growing season
350 days
frost-free stretch
USDA zone
≈ 10b
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Dec 16 Jan 9 Feb 25
First fall frost Jan 27 Dec 25 Dec 1
Hard freeze (28°F), median last Dec 31 · first Dec 29

Computed from NOAA 1991–2020 climate normals at the RIVERSIDE FIRE STN 3 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 Fire Stn 3

Computed from Riverside Fire Stn 3's own frost dates. Click any crop for the full zone-10 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Nov 14 – Nov 28 Jan 16 – Jan 23
🫑 Peppers Oct 31 – Nov 14 Jan 23 – Jan 30
🥬 Lettuce Nov 28 – Dec 12 Dec 12 – Dec 26 Dec 12 – Jan 9
🫛 Peas Nov 28 – Dec 12
🥕 Carrots Dec 19 – Jan 9
🥦 Broccoli Nov 21 – Dec 5 Dec 19 – Jan 2
🥬 Kale Nov 28 – Dec 12 Dec 12 – Dec 26 Dec 12 – Dec 26
🥒 Cucumbers Dec 12 – Dec 19 Jan 16 – Jan 23 Jan 16 – Jan 23
🥒 Zucchini Dec 12 – Dec 19 Jan 16 – Jan 23 Jan 16 – Jan 23
🫘 Green Beans (Bush) Jan 16 – Jan 23
🌽 Sweet Corn Jan 16 – Jan 23
🌿 Basil Nov 28 – Dec 12 Jan 16 – Jan 23 Jan 23 – Jan 30
🧄 Garlic Fall: Nov 13 – Dec 11

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 Fire Stn 3's dates automatically after a lookup.

Reading the season in Riverside Fire Stn 3

With roughly 350 frost-free days, Riverside Fire Stn 3 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 Dec 25 is late enough that fall planting is a full second season, not an afterthought.

Frequently asked questions

When is the last frost in Riverside Fire Stn 3, CA?

The average last spring frost in Riverside Fire Stn 3 is around Jan 9, 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 Fire Stn 3, CA?

The average first fall frost in Riverside Fire Stn 3 arrives around Dec 25. 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 Fire Stn 3?

About 350 frost-free days on average, from Jan 9 to Dec 25. That comfortably fits long-season crops like melons and winter squash, plus spring and fall plantings of cool-season vegetables.

What USDA zone is Riverside Fire Stn 3 in?

USDA zone 10b 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.