Frost dates · USDA zone 5b
Frost dates for Ankeny, IA
Ankeny, IA sees its last 32 °F night of spring around April 23 and its first of fall around October 15 — a 173-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 8 | Oct 28 |
| Median — 1 year in 2 | Apr 23 | Oct 15 |
| 1 year in 10 | May 6 | Sep 30 |
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: 173 days median, at least 154 in 9 years of 10, at least 193 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 13 and first of Oct 25.
Ankeny planting calendar, 2027
Every row runs from the median last frost (Apr 23) and median first frost (Oct 15) 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 Ankeny grow?
Each sauce, scheduled for a Ankeny container garden: when the first seeds go in and when enough fruit has ripened for one batch.
Ankeny frost questions
When is the last frost in Ankeny, IA?
The median last 32 °F freeze at ANKENY, IA is April 23: 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 8. Source: NOAA NCEI 1991–2020 U.S. Climate Normals.
When is the first frost in Ankeny, IA?
The median first 32 °F freeze of fall is October 15. One year in ten it arrives before September 30; nine years in ten, before October 28.
How long is the growing season in Ankeny, IA?
173 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 154 days; one year in ten, at least 193 days.
What growing zone is Ankeny, IA?
USDA hardiness zone 5b, per the 2023 USDA Plant Hardiness Zone Map for ZIP 50023. 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 Ankeny, IA?
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 6. First ripe fruit lands around Jul 14.
When should I plant peppers in Ankeny, IA?
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 Iowa
- Des Moineslast frost Apr 18
- Urbandalelast frost Apr 18
- West Des Moineslast frost Apr 18
- Ameslast frost Apr 26
- Cedar Fallslast frost Apr 27
- Waterloolast frost Apr 27
All Iowa frost dates → · How frost-date math drives a sowing calendar →