Frost dates · USDA zone 6a
Frost dates for Tinley Park, IL
Tinley Park, IL sees its last 32 °F night of spring around April 23 and its first of fall around October 20 — a 179-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 9 | Nov 1 |
| Median — 1 year in 2 | Apr 23 | Oct 20 |
| 1 year in 10 | May 11 | Oct 6 |
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: 179 days median, at least 159 in 9 years of 10, at least 198 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 12 and first of Oct 30.
Tinley Park planting calendar, 2027
Every row runs from the median last frost (Apr 23) and median first frost (Oct 20) 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 29 | Mar 26 | Jul 14 | 110 from transplant |
| Mustard greensGarnet Giant (Brassica juncea) | Direct sow | Apr 23 | May 23 | 30 from sow |
| CilantroSlow Bolt (Coriandrum sativum) | Apr 9 | Apr 9 | May 24 | 45 from sow |
| Genovese BasilGenovese | Mar 26 | May 7 | Jul 6 | 60 from transplant |
| CayenneLong Slim Cayenne (Capsicum annuum) | Feb 26 | Apr 30 | Jul 14 | 75 from transplant |
| HabaneroOrange Habanero (Capsicum chinense) | Feb 12 | May 7 | Aug 10 | 95 from transplant |
| JalapeñoEarly Jalapeño (Capsicum annuum) | Feb 26 | Apr 30 | Jul 14 | 75 from transplant |
| Marconi Red PepperMarconi Red (Capsicum annuum) | Feb 26 | Apr 30 | Jul 19 | 80 from transplant |
| SerranoSerrano Tampiqueño (Capsicum annuum) | Feb 26 | Apr 30 | Jul 19 | 80 from transplant |
| Nantes CarrotScarlet Nantes | Apr 9 | Apr 9 | Jun 18 | 70 from sow |
| TomatilloToma Verde | Mar 12 | Apr 30 | Jul 9 | 70 from transplant |
| Roma TomatoRoma VF (determinate paste) | Mar 12 | Apr 30 | Jul 14 | 75 from transplant |
| San Marzano TomatoSan Marzano (indeterminate paste) | Mar 12 | Apr 30 | Jul 19 | 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 Tinley Park grow?
Each sauce, scheduled for a Tinley Park container garden: when the first seeds go in and when enough fruit has ripened for one batch.
Tinley Park frost questions
When is the last frost in Tinley Park, IL?
The median last 32 °F freeze at PARK FOREST, IL is April 23: half of years see a later one. One year in ten, a freeze still comes after May 11; nine years in ten, it comes after April 9. Source: NOAA NCEI 1991–2020 U.S. Climate Normals.
When is the first frost in Tinley Park, IL?
The median first 32 °F freeze of fall is October 20. One year in ten it arrives before October 6; nine years in ten, before November 1.
How long is the growing season in Tinley Park, IL?
179 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 159 days; one year in ten, at least 198 days.
What growing zone is Tinley Park, IL?
USDA hardiness zone 6a, per the 2023 USDA Plant Hardiness Zone Map for ZIP 60477. 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 Tinley Park, IL?
Start Roma VF (determinate paste) seeds indoors around Mar 12 and transplant around Apr 30, 1 week after the median last frost. To cut the freeze risk to one year in ten, wait for May 11. First ripe fruit lands around Jul 14.
When should I plant peppers in Tinley Park, IL?
Sow jalapeño indoors on a heat mat around Feb 26; transplant no earlier than Apr 30, and wait past it until nights hold above 50 °F — that can run weeks later. First green pods around Jul 14.
Nearby in Illinois
- Orland Parklast frost Apr 20
- Oak Lawnlast frost Apr 10
- Romeovillelast frost Apr 20
- Bolingbrooklast frost Apr 20
- Jolietlast frost Apr 19
- Berwynlast frost Apr 11
All Illinois frost dates → · How frost-date math drives a sowing calendar →