Frost Dates for Owatonna, MN

In Owatonna, MN, the average last spring frost is around May 5 and the average first fall frost around Oct 6, for a growing season of about 154 days. For frost-tender plants, wait until May 20, when the chance of frost drops to 10%.

Average last frostMay 550% chance of frost after this date
Safe to plantMay 20only a 10% chance of frost after
Average first frostOct 650% chance of frost before this date
Growing season154 daysfrost-free in an average year

Based on NOAA 1991–2020 records from the Owatonna, MN weather station, under 1 mile away, elevation 1,140 ft. Frost can come earlier in low spots and valleys and later near cities and large lakes.

Frost probability by date

Chance of a 32°F frost after the spring date, or before the fall date.

ChanceLast spring frostFirst fall frost
10%May 20Sep 23
20%May 14Sep 28
30%May 10Oct 1
40%May 8Oct 4
50%May 5Oct 6
60%May 2Oct 9
70%Apr 30Oct 12
80%Apr 25Oct 16
90%Apr 20Oct 21

Light frost vs. hard freeze

Average (50%) dates for each temperature. Tender plants are damaged at 36°F; most hardy crops survive until 28°F.

TemperatureLast in springFirst in fall
Light frost (36°F)May 14Sep 29
Frost / freeze (32°F)May 5Oct 6
Hard freeze (28°F)Apr 25Oct 18

Planting calendar for Owatonna

Start indoors Plant outside Fall planting
JanFebMarAprMayJunJulAugSepOctNovDec
Tomatoes
Indoors Mar 10 – Mar 24
Transplant May 12 – May 26
Peppers
Indoors Feb 24 – Mar 10
Transplant May 19 – Jun 2
Eggplant
Indoors Feb 24 – Mar 10
Transplant May 19 – Jun 2
Basil
Indoors Mar 24 – Apr 7
Transplant May 12 – May 26
Cucumbers
Indoors Apr 7 – Apr 14
Sow or transplant May 12 – May 26
Zucchini and summer squash
Indoors Apr 7 – Apr 14
Sow or transplant May 12 – May 26
Pumpkins and winter squash
Sow May 12 – May 26
Watermelons and melons
Indoors Apr 7 – Apr 14
Sow or transplant May 19 – Jun 2
Green beans
Sow May 12 – May 26
Sweet corn
Sow May 12 – May 26
Lettuce
Indoors Mar 24 – Apr 7
Sow or transplant Apr 7 – Apr 21
Fall sowing Aug 11 – Sep 8
Spinach
Sow Mar 24 – Apr 14
Fall sowing Aug 11 – Sep 1
Peas
Sow Mar 24 – Apr 7
Fall sowing Jul 28 – Aug 11
Kale
Indoors Mar 10 – Mar 24
Sow or transplant Apr 7 – Apr 21
Fall sowing Jul 28 – Aug 25
Broccoli
Indoors Mar 10 – Mar 24
Transplant Apr 21 – May 5
Fall sowing Jul 14 – Jul 28
Cabbage
Indoors Mar 10 – Mar 24
Transplant Apr 14 – Apr 28
Fall sowing Jul 14 – Jul 28
Carrots
Sow Apr 14 – May 5
Fall sowing Jul 14 – Jul 28
Radishes
Sow Mar 31 – Apr 21
Fall sowing Aug 25 – Sep 15
Beets
Sow Apr 14 – May 5
Fall sowing Jul 28 – Aug 11
Onions (sets or transplants)
Indoors Feb 10 – Feb 24
Plant Apr 7 – Apr 21
Potatoes
Plant Apr 14 – Apr 28
Garlic
Plant Oct 6 – Nov 3

Based on the average last frost (May 5) and first frost (Oct 6). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.

Nearby cities

AustinMankatoRochesterLakevillePrior LakeApple ValleyRosemountBurnsvilleAll Minnesota towns