Mosby 4 ENE, MT Frost Dates & Growing Season

The two dates every Mosby 4 ENE garden is planned around, plus ready-computed planting windows for the most popular crops.

Last spring frost
May 5
~50% chance of frost after
First fall frost
Oct 4
~50% chance of frost before
Growing season
152 days
frost-free stretch
USDA zone
≈ 5a
estimated from nearby reference
Risky (1 year in 10)MedianSafe (9 years in 10)
Last spring frost Apr 20 May 5 May 26
First fall frost Oct 19 Oct 4 Sep 22
Hard freeze (28°F), median last Apr 20 · first Oct 14

Computed from NOAA 1991–2020 climate normals at the MOSBY 4 ENE 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 Mosby 4 ENE

Computed from Mosby 4 ENE's own frost dates. Click any crop for the full zone-5 growing guide — varieties, spacing, fall plantings, and more.

CropStart seeds indoorsTransplantDirect sow
🍅 Tomatoes Mar 10 – Mar 24 May 12 – May 19
🫑 Peppers Feb 24 – Mar 10 May 19 – May 26
🥬 Lettuce Mar 24 – Apr 7 Apr 7 – Apr 21 Apr 7 – May 5
🫛 Peas Mar 24 – Apr 7
🥕 Carrots Apr 14 – May 5
🥦 Broccoli Mar 17 – Mar 31 Apr 14 – Apr 28
🥬 Kale Mar 24 – Apr 7 Apr 7 – Apr 21 Apr 7 – Apr 21
🥒 Cucumbers Apr 7 – Apr 14 May 12 – May 19 May 12 – May 19
🥒 Zucchini Apr 7 – Apr 14 May 12 – May 19 May 12 – May 19
🫘 Green Beans (Bush) May 12 – May 19
🌽 Sweet Corn May 12 – May 19
🌿 Basil Mar 24 – Apr 7 May 12 – May 19 May 19 – May 26
🧄 Garlic Fall: Aug 23 – Sep 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 Mosby 4 ENE's dates automatically after a lookup.

Reading the season in Mosby 4 ENE

Roughly 152 frost-free days gives Mosby 4 ENE gardeners room for nearly every common vegetable. Warm-season crops go out after May 5; a fall garden sown in late summer matures comfortably before the Oct 4 frost.

Frequently asked questions

When is the last frost in Mosby 4 ENE, MT?

The average last spring frost in Mosby 4 ENE is around May 5, 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 Mosby 4 ENE, MT?

The average first fall frost in Mosby 4 ENE arrives around Oct 4. 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 Mosby 4 ENE?

About 152 frost-free days on average, from May 5 to Oct 4. That fits nearly all common vegetables, though the longest-season melons and sweet potatoes benefit from transplants.

What USDA zone is Mosby 4 ENE in?

USDA zone 5a 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.