Bloomington, Minnesota: planting zone & frost dates
Bloomington is in USDA plant hardiness zone 5a, where the average coldest winter night reaches -20 to -15°F (-28.9 to -26.1°C). The typical last spring frost is around Apr 30 and the first fall frost around Oct 11.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | May 7 | Oct 1 |
| Typical planning date (30% risk) | Apr 30 | Oct 11 |
| Median (50%) | Apr 23 | Oct 18 |
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 MINNEAPOLIS/ST PAUL AP, MN (USW00014922), 5.6 mi (9.0 km) from the city center and 62 ft higher than the city center (+19 m). Record used for the 1991–2020 normals: 27 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Bloomington
All 5 ZIP codes covering Bloomington are in zone 5a.
Vegetable planting calendar for Bloomington
Dates are counted from the 30%-risk frost dates above (last frost Apr 30, first frost Oct 11). 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 5 – Mar 19 | May 7 – May 21 | — | — |
| Pepper | Feb 19 – Mar 5 | May 14 – May 28 | — | — |
| Lettuce | Mar 19 – Apr 2 | Apr 16 – May 7 | Apr 2 – May 14 | Aug 2 – Aug 30 |
| Green Beans | — | — | May 7 – Jun 11 | Jul 19 – Aug 2 |
| Sweet Corn | — | — | May 7 – Jun 4 | — |
| Zucchini & Summer Squash | Apr 2 – Apr 9 | May 7 – May 21 | May 7 – May 28 | Jul 19 – Aug 2 |
| Cucumber | Apr 2 – Apr 9 | May 14 – May 21 | May 7 – May 28 | Jul 19 – Aug 2 |
| Carrot | — | — | Apr 9 – May 14 | Jul 19 – Aug 2 |
| Onion | Feb 5 – Feb 19 | Apr 2 – Apr 16 | — | — |
| Potato | — | Apr 2 – Apr 23 | — | — |
| Basil | Mar 19 – Apr 2 | May 14 – May 28 | May 14 – Jun 4 | — |
| Spinach | — | — | Mar 19 – Apr 16 | Aug 16 – Sep 13 |
| Kale | Mar 5 – Mar 19 | Apr 2 – Apr 23 | Apr 2 – Apr 23 | Aug 2 – Aug 30 |
| Broccoli | Mar 5 – Mar 19 | Apr 16 – May 7 | — | Jul 19 – Aug 2 |
| Peas | — | — | Mar 19 – Apr 9 | Aug 2 – Aug 16 |
| Eggplant | Feb 19 – Mar 5 | May 14 – May 28 | — | — |
| Cabbage | Mar 5 – Mar 19 | Apr 2 – Apr 16 | — | Jul 19 – Aug 2 |
| Radish | — | — | Mar 26 – May 14 | Aug 30 – Sep 27 |
| Strawberry | — | Apr 2 – Apr 23 | — | — |
| Beets | — | — | Apr 9 – May 21 | Aug 2 – Aug 16 |
Nearby cities in Minnesota
- Minneapolis — zone 5a, last frost Apr 30, first frost Oct 10
- Lakeville — zone 4b, last frost May 2, first frost Oct 4
- St. Paul — zone 5a, last frost May 1, first frost Oct 7
- Plymouth — zone 5a, last frost May 4, first frost Oct 5
- Brooklyn Park — zone 5a, last frost May 6, first frost Oct 2
- Woodbury — zone 5a, last frost May 1, first frost Oct 5
More: all Minnesota cities · other zone 5a cities: Minneapolis, MN, St. Paul, MN, Anchorage, AK, Sioux Falls, SD, Cedar Rapids, IA, Billings, MT, Sioux City, IA, Brooklyn Park, MN
Bloomington gardening questions
When is the last frost in Bloomington, MN?
Plan around Apr 30. At NOAA's Minneapolis/st Paul Airport, MN station, 5.6 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 23, and after May 7 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 13. The 90% and 10% dates are 29 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in Bloomington, MN?
Start seeds indoors Mar 5 – Mar 19 and set transplants outside May 7 – May 21, once nights stay above 50°F and the soil is near 60°F. That leaves 164 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 176 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 158 days, and in 1 year in 10 it runs 196 days or more. In fall there is a 10% chance of frost by Oct 1 and a 30% chance by Oct 11. That is the longest of the 9 Minnesota cities on this site.
When should I plant a fall garden in Bloomington?
Count back from the first fall frost (Oct 11): transplant broccoli Jul 19 – Aug 2; sow kale Aug 2 – Aug 30; sow lettuce Aug 2 – Aug 30; sow radishes Aug 30 – Sep 27. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Oct 29. How the math works: succession and fall planting.
Did Bloomington's hardiness zone change on the 2023 map?
Yes. Most of Bloomington was zone 4b on the 2012 map and is zone 5a 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 Minneapolis, MN?
Both are in zone 5a. The typical last spring frost in Bloomington (Apr 30) comes about the same time as in Minneapolis, MN (Apr 30), 10 miles away, and the first fall frost is Oct 11 versus Oct 10. The two cities use different NOAA stations.