Frost dates · USDA zone 5a
Frost dates for Mankato, MN
Mankato, MN sees its last 32 °F night of spring around April 30 and its first of fall around October 9 — a 161-day freeze-free season in a typical year.
Pick a sauce; the Plan Builder runs this station's dates and hands back the calendar, plant count and gear list.
Freeze odds, by date
| Odds | Last spring freeze after | First fall freeze before |
|---|---|---|
| 9 years in 10 | Apr 16 | Oct 22 |
| Median — 1 year in 2 | Apr 30 | Oct 9 |
| 1 year in 10 | May 12 | Sep 25 |
The top row is the risky edge: in 9 years of 10 a spring freeze still comes after it, so tender transplants set out then need cover. The bottom row is the cautious date — only 1 year in 10 freezes after it — and the one to plan uncovered tender transplants against. Freeze-free season: 161 days median, at least 141 in 9 years of 10, at least 179 days in 1 year of 10. NOAA ranks season length year by year, so it is not the gap between two rows above. A hard freeze (28 °F) has a median last date of Apr 19 and first of Oct 20.
Mankato planting calendar, 2027
Every row runs from the median last frost (Apr 30) and median first frost (Oct 9) above, using each cultivar's days to maturity. Same engine as the Plan Builder.
| Crop | Start indoors | Transplant / plant | First harvest | Days |
|---|---|---|---|---|
| Hardneck GarlicSiberian (porcelain hardneck) | — | Oct 15prior fall | Jun 12 | 240 from sow |
| Spanish OnionYellow Sweet Spanish (long-day) | Feb 5 | Apr 2 | Jul 21 | 110 from transplant |
| Mustard greensGarnet Giant (Brassica juncea) | Direct sow | Apr 30 | May 30 | 30 from sow |
| CilantroSlow Bolt (Coriandrum sativum) | Apr 16 | Apr 16 | May 31 | 45 from sow |
| Genovese BasilGenovese | Apr 2 | May 14 | Jul 13 | 60 from transplant |
| CayenneLong Slim Cayenne (Capsicum annuum) | Mar 5 | May 7 | Jul 21 | 75 from transplant |
| HabaneroOrange Habanero (Capsicum chinense) | Feb 19 | May 14 | Aug 17 | 95 from transplant |
| JalapeñoEarly Jalapeño (Capsicum annuum) | Mar 5 | May 7 | Jul 21 | 75 from transplant |
| Marconi Red PepperMarconi Red (Capsicum annuum) | Mar 5 | May 7 | Jul 26 | 80 from transplant |
| SerranoSerrano Tampiqueño (Capsicum annuum) | Mar 5 | May 7 | Jul 26 | 80 from transplant |
| Nantes CarrotScarlet Nantes | Apr 16 | Apr 16 | Jun 25 | 70 from sow |
| TomatilloToma Verde | Mar 19 | May 7 | Jul 16 | 70 from transplant |
| Roma TomatoRoma VF (determinate paste) | Mar 19 | May 7 | Jul 21 | 75 from transplant |
| San Marzano TomatoSan Marzano (indeterminate paste) | Mar 19 | May 7 | Jul 26 | 80 from transplant |
Tight means first harvest lands within two weeks of the median first fall frost: start that crop indoors on time or cover it in fall.
What sauce can Mankato grow?
Each sauce, scheduled for a Mankato container garden: when the first seeds go in and when enough fruit has ripened for one batch.
Mankato frost questions
When is the last frost in Mankato, MN?
The median last 32 °F freeze at MANKATO, MN is April 30: half of years see a later one. One year in ten, a freeze still comes after May 12; nine years in ten, it comes after April 16. Source: NOAA NCEI 1991–2020 U.S. Climate Normals.
When is the first frost in Mankato, MN?
The median first 32 °F freeze of fall is October 9. One year in ten it arrives before September 25; nine years in ten, before October 22.
How long is the growing season in Mankato, MN?
161 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 141 days; one year in ten, at least 179 days.
What growing zone is Mankato, MN?
USDA hardiness zone 5a, per the 2023 USDA Plant Hardiness Zone Map for ZIP 56001. A zone describes the coldest winter night, not when frost ends, so it is the wrong number for a planting calendar — the frost dates on this page are the right one.
When should I plant tomatoes in Mankato, MN?
Start Roma VF (determinate paste) seeds indoors around Mar 19 and transplant around May 7, 1 week after the median last frost. To cut the freeze risk to one year in ten, wait for May 12. First ripe fruit lands around Jul 21.
When should I plant peppers in Mankato, MN?
Sow jalapeño indoors on a heat mat around Mar 5; transplant no earlier than May 7, and wait past it until nights hold above 50 °F — that can run weeks later. First green pods around Jul 21.
Nearby in Minnesota
- Shakopeelast frost Apr 23
- Lakevillelast frost Apr 27
- Eden Prairielast frost Apr 23
- Burnsvillelast frost Apr 23
- Apple Valleylast frost May 2
- Bloomingtonlast frost Apr 23
All Minnesota frost dates → · How frost-date math drives a sowing calendar →