Frost dates · USDA zone 6b
Frost dates for Warren, MI
Warren, MI sees its last 32 °F night of spring around April 21 and its first of fall around October 31 — a 190-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 7 | Nov 11 |
| Median — 1 year in 2 | Apr 21 | Oct 31 |
| 1 year in 10 | May 6 | Oct 17 |
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: 190 days median, at least 171 in 9 years of 10, at least 208 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 8 and first of Nov 9.
Warren planting calendar, 2027
Every row runs from the median last frost (Apr 21) and median first frost (Oct 31) 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) | Jan 27 | Mar 24 | Jul 12 | 110 from transplant |
| Mustard greensGarnet Giant (Brassica juncea) | Direct sow | Apr 21 | May 21 | 30 from sow |
| CilantroSlow Bolt (Coriandrum sativum) | Apr 7 | Apr 7 | May 22 | 45 from sow |
| Genovese BasilGenovese | Mar 24 | May 5 | Jul 4 | 60 from transplant |
| CayenneLong Slim Cayenne (Capsicum annuum) | Feb 24 | Apr 28 | Jul 12 | 75 from transplant |
| HabaneroOrange Habanero (Capsicum chinense) | Feb 10 | May 5 | Aug 8 | 95 from transplant |
| JalapeñoEarly Jalapeño (Capsicum annuum) | Feb 24 | Apr 28 | Jul 12 | 75 from transplant |
| Marconi Red PepperMarconi Red (Capsicum annuum) | Feb 24 | Apr 28 | Jul 17 | 80 from transplant |
| SerranoSerrano Tampiqueño (Capsicum annuum) | Feb 24 | Apr 28 | Jul 17 | 80 from transplant |
| Nantes CarrotScarlet Nantes | Apr 7 | Apr 7 | Jun 16 | 70 from sow |
| TomatilloToma Verde | Mar 10 | Apr 28 | Jul 7 | 70 from transplant |
| Roma TomatoRoma VF (determinate paste) | Mar 10 | Apr 28 | Jul 12 | 75 from transplant |
| San Marzano TomatoSan Marzano (indeterminate paste) | Mar 10 | Apr 28 | Jul 17 | 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 Warren grow?
Each sauce, scheduled for a Warren container garden: when the first seeds go in and when enough fruit has ripened for one batch.
Warren frost questions
When is the last frost in Warren, MI?
The median last 32 °F freeze at DETROIT CITY AP, MI is April 21: half of years see a later one. One year in ten, a freeze still comes after May 6; nine years in ten, it comes after April 7. Source: NOAA NCEI 1991–2020 U.S. Climate Normals.
When is the first frost in Warren, MI?
The median first 32 °F freeze of fall is October 31. One year in ten it arrives before October 17; nine years in ten, before November 11.
How long is the growing season in Warren, MI?
190 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 171 days; one year in ten, at least 208 days.
What growing zone is Warren, MI?
USDA hardiness zone 6b, per the 2023 USDA Plant Hardiness Zone Map for ZIP 48015. 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 Warren, MI?
Start Roma VF (determinate paste) seeds indoors around Mar 10 and transplant around Apr 28, 1 week after the median last frost. To cut the freeze risk to one year in ten, wait for May 6. First ripe fruit lands around Jul 12.
When should I plant peppers in Warren, MI?
Sow jalapeño indoors on a heat mat around Feb 24; transplant no earlier than Apr 28, and wait past it until nights hold above 50 °F — that can run weeks later. First green pods around Jul 12.
Nearby in Michigan
- Rosevillelast frost Apr 29
- Sterling Heightslast frost Apr 30
- Royal Oaklast frost Apr 26
- St. Clair Shoreslast frost Apr 29
- Detroitlast frost Apr 27
- Troylast frost Apr 26
All Michigan frost dates → · How frost-date math drives a sowing calendar →