Bloomington, Indiana: planting zone & frost dates
Bloomington is in USDA plant hardiness zone 6b, where the average coldest winter night reaches -5 to 0°F (-20.6 to -17.8°C). The typical last spring frost is around Apr 22 and the first fall frost around Oct 21.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | May 3 | Oct 11 |
| Typical planning date (30% risk) | Apr 22 | Oct 21 |
| Median (50%) | Apr 15 | Oct 26 |
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 BLOOMINGTON INDIANA UNIV, IN (USC00120784), 0.7 mi (1.2 km) from the city center and 13 ft higher than the city center (+4 m). Record used for the 1991–2020 normals: 28 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Bloomington
All 6 ZIP codes covering Bloomington are in zone 6b.
Vegetable planting calendar for Bloomington
Dates are counted from the 30%-risk frost dates above (last frost Apr 22, first frost Oct 21). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Feb 25 – Mar 11 | Apr 29 – May 13 | — | — |
| Pepper | Feb 11 – Feb 25 | May 6 – May 20 | — | — |
| Lettuce | Mar 11 – Mar 25 | Apr 8 – Apr 29 | Mar 25 – May 6 | Aug 12 – Sep 9 |
| Green Beans | — | — | Apr 29 – Jun 3 | Jul 29 – Aug 12 |
| Sweet Corn | — | — | Apr 29 – May 27 | — |
| Zucchini & Summer Squash | Mar 25 – Apr 1 | Apr 29 – May 13 | Apr 29 – May 20 | Jul 29 – Aug 12 |
| Cucumber | Mar 25 – Apr 1 | May 6 – May 13 | Apr 29 – May 20 | Jul 29 – Aug 12 |
| Carrot | — | — | Apr 1 – May 6 | Jul 29 – Aug 12 |
| Onion | Jan 28 – Feb 11 | Mar 25 – Apr 8 | — | — |
| Potato | — | Mar 25 – Apr 15 | — | — |
| Basil | Mar 11 – Mar 25 | May 6 – May 20 | May 6 – May 27 | — |
| Spinach | — | — | Mar 11 – Apr 8 | Aug 26 – Sep 23 |
| Kale | Feb 25 – Mar 11 | Mar 25 – Apr 15 | Mar 25 – Apr 15 | Aug 12 – Sep 9 |
| Broccoli | Feb 25 – Mar 11 | Apr 8 – Apr 29 | — | Jul 29 – Aug 12 |
| Peas | — | — | Mar 11 – Apr 1 | Aug 12 – Aug 26 |
| Eggplant | Feb 11 – Feb 25 | May 6 – May 20 | — | — |
| Cabbage | Feb 25 – Mar 11 | Mar 25 – Apr 8 | — | Jul 29 – Aug 12 |
| Radish | — | — | Mar 18 – May 6 | Sep 9 – Oct 7 |
| Strawberry | — | Mar 25 – Apr 15 | — | — |
| Beets | — | — | Apr 1 – May 13 | Aug 12 – Aug 26 |
Nearby cities in Indiana
- Indianapolis — zone 6b, last frost Apr 26, first frost Oct 16
- Carmel — zone 6a, last frost Apr 28, first frost Oct 15
- Fishers — zone 6a, last frost Apr 28, first frost Oct 15
- Evansville — zone 7a, last frost Apr 2, first frost Nov 4
- Fort Wayne — zone 6a, last frost May 1, first frost Oct 16
- South Bend — zone 6a, last frost May 7, first frost Oct 14
More: all Indiana cities · other zone 6b cities: Columbus, OH, Indianapolis, IN, Boston, MA, Detroit, MI, Kansas City, MO, Cincinnati, OH, Pittsburgh, PA, Buffalo, NY
Bloomington gardening questions
When is the last frost in Bloomington, IN?
Plan around Apr 22. At NOAA's Bloomington Indiana Univ., IN station, 0.7 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 15, and after May 3 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 2. 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 Bloomington, IN?
Start seeds indoors Feb 25 – Mar 11 and set transplants outside Apr 29 – May 13, once nights stay above 50°F and the soil is near 60°F. That leaves 182 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 Bloomington?
About 192 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 169 days, and in 1 year in 10 it runs 214 days or more. In fall there is a 10% chance of frost by Oct 11 and a 30% chance by Oct 21. That ranks 2nd longest of 8 Indiana cities on this site.
When should I plant a fall garden in Bloomington?
Count back from the first fall frost (Oct 21): transplant broccoli Jul 29 – Aug 12; sow kale Aug 12 – Sep 9; sow lettuce Aug 12 – Sep 9; sow radishes Sep 9 – Oct 7. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 4. How the math works: succession and fall planting.
Did Bloomington's hardiness zone change on the 2023 map?
Yes. Most of Bloomington was zone 6a on the 2012 map and is zone 6b 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 Bloomington compare with Indianapolis, IN?
Both are in zone 6b. The typical last spring frost in Bloomington (Apr 22) comes about 4 days earlier than in Indianapolis, IN (Apr 26), 47 miles away, and the first fall frost is Oct 21 versus Oct 16. The two cities use different NOAA stations.