Carmel, Indiana: planting zone & frost dates
Carmel is in USDA plant hardiness zone 6a, where the average coldest winter night reaches -10 to -5°F (-23.3 to -20.6°C). The typical last spring frost is around Apr 28 and the first fall frost around Oct 15.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | May 8 | Oct 6 |
| Typical planning date (30% risk) | Apr 28 | Oct 15 |
| Median (50%) | Apr 21 | Oct 21 |
How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.
Frost data comes from NOAA station CARMEL 3 E, IN (USC00121303), 4.8 mi (7.7 km) from the city center and 92 ft lower than the city center (-28 m). Record used for the 1991–2020 normals: 20 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Carmel
All 6 ZIP codes covering Carmel are in zone 6a.
Vegetable planting calendar for Carmel
Dates are counted from the 30%-risk frost dates above (last frost Apr 28, first frost Oct 15). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Mar 3 – Mar 17 | May 5 – May 19 | — | — |
| Pepper | Feb 17 – Mar 3 | May 12 – May 26 | — | — |
| Lettuce | Mar 17 – Mar 31 | Apr 14 – May 5 | Mar 31 – May 12 | Aug 6 – Sep 3 |
| Green Beans | — | — | May 5 – Jun 9 | Jul 23 – Aug 6 |
| Sweet Corn | — | — | May 5 – Jun 2 | — |
| Zucchini & Summer Squash | Mar 31 – Apr 7 | May 5 – May 19 | May 5 – May 26 | Jul 23 – Aug 6 |
| Cucumber | Mar 31 – Apr 7 | May 12 – May 19 | May 5 – May 26 | Jul 23 – Aug 6 |
| Carrot | — | — | Apr 7 – May 12 | Jul 23 – Aug 6 |
| Onion | Feb 3 – Feb 17 | Mar 31 – Apr 14 | — | — |
| Potato | — | Mar 31 – Apr 21 | — | — |
| Basil | Mar 17 – Mar 31 | May 12 – May 26 | May 12 – Jun 2 | — |
| Spinach | — | — | Mar 17 – Apr 14 | Aug 20 – Sep 17 |
| Kale | Mar 3 – Mar 17 | Mar 31 – Apr 21 | Mar 31 – Apr 21 | Aug 6 – Sep 3 |
| Broccoli | Mar 3 – Mar 17 | Apr 14 – May 5 | — | Jul 23 – Aug 6 |
| Peas | — | — | Mar 17 – Apr 7 | Aug 6 – Aug 20 |
| Eggplant | Feb 17 – Mar 3 | May 12 – May 26 | — | — |
| Cabbage | Mar 3 – Mar 17 | Mar 31 – Apr 14 | — | Jul 23 – Aug 6 |
| Radish | — | — | Mar 24 – May 12 | Sep 3 – Oct 1 |
| Strawberry | — | Mar 31 – Apr 21 | — | — |
| Beets | — | — | Apr 7 – May 19 | Aug 6 – Aug 20 |
Nearby cities in Indiana
- Fishers — zone 6a, last frost Apr 28, first frost Oct 15
- Indianapolis — zone 6b, last frost Apr 26, first frost Oct 16
- Bloomington — zone 6b, last frost Apr 22, first frost Oct 21
- Fort Wayne — zone 6a, last frost May 1, first frost Oct 16
- South Bend — zone 6a, last frost May 7, first frost Oct 14
- Hammond — zone 6a, last frost Apr 30, first frost Oct 15
More: all Indiana cities · other zone 6a cities: Chicago, IL, Denver, CO, Milwaukee, WI, Colorado Springs, CO, Omaha, NE, Aurora, CO, Lincoln, NE, Fort Wayne, IN
Carmel gardening questions
When is the last frost in Carmel, IN?
Plan around Apr 28. At NOAA's Carmel 3 E, IN station, 4.8 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Apr 21, and after May 8 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 8. The 90% and 10% dates are 33 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in Carmel, IN?
Start seeds indoors Mar 3 – Mar 17 and set transplants outside May 5 – May 19, once nights stay above 50°F and the soil is near 60°F. That leaves 170 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.
How long is the growing season in Carmel?
About 183 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 160 days, and in 1 year in 10 it runs 204 days or more. In fall there is a 10% chance of frost by Oct 6 and a 30% chance by Oct 15. That ranks 5th longest of 8 Indiana cities on this site.
When should I plant a fall garden in Carmel?
Count back from the first fall frost (Oct 15): transplant broccoli Jul 23 – Aug 6; sow kale Aug 6 – Sep 3; sow lettuce Aug 6 – Sep 3; sow radishes Sep 3 – Oct 1. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 1. How the math works: succession and fall planting.
Did Carmel's hardiness zone change on the 2023 map?
Yes. Most of Carmel was zone 5b on the 2012 map and is zone 6a on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.
How does Carmel compare with Indianapolis, IN?
Carmel is zone 6a and Indianapolis is zone 6b. The typical last spring frost in Carmel (Apr 28) comes about the same time as in Indianapolis, IN (Apr 26), 13 miles away, and the first fall frost is Oct 15 versus Oct 16. The two cities use different NOAA stations.