US Grow Zones

Hammond, Indiana: planting zone & frost dates

Last updated · Sources: PRISM/OSU 2023 ZIP zone listings; NOAA NCEI 1991–2020 Climate Normals (station USC00116616); U.S. Census Bureau — see methodology

Hammond 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 30 and the first fall frost around Oct 15.

Hardiness zone6A-10 to -5°F
Last spring frostApr 3030% chance of frost after
First fall frostOct 1530% chance of frost before
Growing season179 daysmedian frost-free days

Frost dates

ProbabilityLast spring frost (32°F)First fall frost (32°F)
Safer (10% risk)May 11Oct 6
Typical planning date (30% risk)Apr 30Oct 15
Median (50%)Apr 23Oct 20

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 PARK FOREST, IL (USC00116616), 12.9 mi (20.7 km) from the city center and 121 ft higher than the city center (+37 m). Record used for the 1991–2020 normals: 26 years.

Frost probability in spring and fall, Hammond, INChance of a 32°F frost in Hammond, IN, NOAA 1991–2020. Spring: the chance of another frost falls from 90% on Apr 9 to 10% on May 11. Fall: the chance that the first frost has arrived rises from 10% on Oct 6 to 90% on Nov 1.0%50%100%Spring: later frostApr 1Apr 15May 1May 1530%: Apr 30Fall: frost arrivedOct 1Oct 15Nov 1Nov 1530%: Oct 1532°F frost28°F hard freezeplanning date
Shaded areas show the chance of a 32°F frost: falling through spring, rising through fall. The dashed line is the 28°F hard-freeze curve. Data: NOAA 1991–2020 Normals, station USC00116616.
Frost-free growing season in Hammond, IN1 in 10 risk: May 11 to Oct 6 (148 days); 3 in 10 risk: Apr 30 to Oct 15 (168 days); Median (50%): Apr 23 to Oct 20 (180 days); No 28°F freeze: Apr 12 to Oct 30 (201 days). In 9 of 10 years the 32°F-free season is at least 159 days.Frost-free days, spring to fallJFMAMJJASOND1 in 10 risk148 days3 in 10 risk168 daysMedian (50%)180 daysNo 28°F freeze201 days
Frost-free window at three risk levels, plus the window between 28°F hard freezes. Read about what the probabilities mean.

Why your yard may differ from the station: microclimates.

Hardiness zone across Hammond

All 5 ZIP codes covering Hammond are in zone 6a.

ZIP codes in Hammond and their zones
ZIPZoneShare of city land
463236a27.2%
463206a20.2%
463276a20.2%
463246a19.2%
463946a12.9%

Vegetable planting calendar for Hammond

Dates are counted from the 30%-risk frost dates above (last frost Apr 30, first frost Oct 15). Shift a week later in cold spots or low-lying ground.

CropStart indoorsTransplant / plant outDirect sowFall crop sow/plant
TomatoMar 5 – Mar 19May 7 – May 21——
PepperFeb 19 – Mar 5May 14 – May 28——
LettuceMar 19 – Apr 2Apr 16 – May 7Apr 2 – May 14Aug 6 – Sep 3
Green Beans——May 7 – Jun 11Jul 23 – Aug 6
Sweet Corn——May 7 – Jun 4—
Zucchini & Summer SquashApr 2 – Apr 9May 7 – May 21May 7 – May 28Jul 23 – Aug 6
CucumberApr 2 – Apr 9May 14 – May 21May 7 – May 28Jul 23 – Aug 6
Carrot——Apr 9 – May 14Jul 23 – Aug 6
OnionFeb 5 – Feb 19Apr 2 – Apr 16——
Potato—Apr 2 – Apr 23——
BasilMar 19 – Apr 2May 14 – May 28May 14 – Jun 4—
Spinach——Mar 19 – Apr 16Aug 20 – Sep 17
KaleMar 5 – Mar 19Apr 2 – Apr 23Apr 2 – Apr 23Aug 6 – Sep 3
BroccoliMar 5 – Mar 19Apr 16 – May 7—Jul 23 – Aug 6
Peas——Mar 19 – Apr 9Aug 6 – Aug 20
EggplantFeb 19 – Mar 5May 14 – May 28——
CabbageMar 5 – Mar 19Apr 2 – Apr 16—Jul 23 – Aug 6
Radish——Mar 26 – May 14Sep 3 – Oct 1
Strawberry—Apr 2 – Apr 23——
Beets——Apr 9 – May 21Aug 6 – Aug 20

Nearby cities in Indiana

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

Hammond gardening questions

When is the last frost in Hammond, IN?

Plan around Apr 30. At NOAA's Park Forest, IL station, 12.9 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 11 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 12. The 90% and 10% dates are 32 days apart, close to the 36-day median for cities on this site.

When should I plant tomatoes in Hammond, IN?

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 168 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 Hammond?

About 179 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 159 days, and in 1 year in 10 it runs 198 days or more. In fall there is a 10% chance of frost by Oct 6 and a 30% chance by Oct 15. That ranks 6th longest of 8 Indiana cities on this site.

When should I plant a fall garden in Hammond?

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 Oct 30. How the math works: succession and fall planting.

Did Hammond's hardiness zone change on the 2023 map?

Yes. Most of Hammond 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 Hammond compare with Chicago, IL?

Both are in zone 6a. The typical last spring frost in Hammond (Apr 30) comes about 13 days later than in Chicago, IL (Apr 17), 18 miles away, and the first fall frost is Oct 15 versus Nov 1. The two cities use different NOAA stations.