Frost dates · USDA zone 6a
Frost dates for Centennial, CO
Centennial, CO sees its last 32 °F night of spring around May 5 and its first of fall around October 8 — a 154-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 24 | Oct 20 |
| Median — 1 year in 2 | May 5 | Oct 8 |
| 1 year in 10 | May 17 | 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: 154 days median, at least 135 in 9 years of 10, at least 170 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 25 and first of Oct 17.
Centennial planting calendar, 2027
Every row runs from the median last frost (May 5) and median first frost (Oct 8) 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 10 | Apr 7 | Jul 26 | 110 from transplant |
| Mustard greensGarnet Giant (Brassica juncea) | Direct sow | May 5 | Jun 4 | 30 from sow |
| CilantroSlow Bolt (Coriandrum sativum) | Apr 21 | Apr 21 | Jun 5 | 45 from sow |
| Genovese BasilGenovese | Apr 7 | May 19 | Jul 18 | 60 from transplant |
| CayenneLong Slim Cayenne (Capsicum annuum) | Mar 10 | May 12 | Jul 26 | 75 from transplant |
| HabaneroOrange Habanero (Capsicum chinense) | Feb 24 | May 19 | Aug 22 | 95 from transplant |
| JalapeñoEarly Jalapeño (Capsicum annuum) | Mar 10 | May 12 | Jul 26 | 75 from transplant |
| Marconi Red PepperMarconi Red (Capsicum annuum) | Mar 10 | May 12 | Jul 31 | 80 from transplant |
| SerranoSerrano Tampiqueño (Capsicum annuum) | Mar 10 | May 12 | Jul 31 | 80 from transplant |
| Nantes CarrotScarlet Nantes | Apr 21 | Apr 21 | Jun 30 | 70 from sow |
| TomatilloToma Verde | Mar 24 | May 12 | Jul 21 | 70 from transplant |
| Roma TomatoRoma VF (determinate paste) | Mar 24 | May 12 | Jul 26 | 75 from transplant |
| San Marzano TomatoSan Marzano (indeterminate paste) | Mar 24 | May 12 | Jul 31 | 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 Centennial grow?
Each sauce, scheduled for a Centennial container garden: when the first seeds go in and when enough fruit has ripened for one batch.
Centennial frost questions
When is the last frost in Centennial, CO?
The median last 32 °F freeze at DENVER CENTENNIAL AP, CO is May 5: half of years see a later one. One year in ten, a freeze still comes after May 17; nine years in ten, it comes after April 24. Source: NOAA NCEI 1991–2020 U.S. Climate Normals.
When is the first frost in Centennial, CO?
The median first 32 °F freeze of fall is October 8. One year in ten it arrives before September 25; nine years in ten, before October 20.
How long is the growing season in Centennial, CO?
154 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 135 days; one year in ten, at least 170 days.
What growing zone is Centennial, CO?
USDA hardiness zone 6a, per the 2023 USDA Plant Hardiness Zone Map for ZIP 80112. 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 Centennial, CO?
Start Roma VF (determinate paste) seeds indoors around Mar 24 and transplant around May 12, 1 week after the median last frost. To cut the freeze risk to one year in ten, wait for May 17. First ripe fruit lands around Jul 26.
When should I plant peppers in Centennial, CO?
Sow jalapeño indoors on a heat mat around Mar 10; transplant no earlier than May 12, and wait past it until nights hold above 50 °F — that can run weeks later. First green pods around Jul 26.
Nearby in Colorado
- Parkerlast frost May 9
- Littletonlast frost May 2
- Auroralast frost May 5
- Denverlast frost May 4
- Castle Rocklast frost May 9
- Lakewoodlast frost May 3
All Colorado frost dates → · How frost-date math drives a sowing calendar →