Frost dates for 46410 — Merrillville, IN
Last spring frostApr 22median date
First fall frostOct 25median date
Growing season186 daysfrost-free
Hardiness zone6aZone 6a
How Merrillville compares
- In 8 years out of 10, the last spring frost in Merrillville falls between April 7 and May 6, a 29-day window. The first fall frost falls between October 12 and November 6.
- The median last frost is the same as the Indiana median of Apr 22.
- Its 186-day growing season is longer than 64% of the 733 Indiana places with a regular frost season (state median 182 days).
- The last frost is 7 days earlier than the zone 6a median of Apr 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6a chart.
- The weather station records an average of 124 nights a year at or below 32°F.
- Compared with Gary, IN, 9 km away, the last frost here is the same as there and the growing season is 2 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 7 |
| 50% (median) | April 22 |
| 10% (safe for tender plants) | May 6 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 12 |
| 50% (median) | October 25 |
| 90% (late) | November 6 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Merrillville, IN
Frost dates for 46410 — Merrillville, IN — last frost Apr 22, first frost Oct 25, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Jan 28 to Feb 11Transplant outside: Mar 25 to Apr 8
Start indoors: Feb 11 to Feb 25Transplant outside: May 6 to May 20
Start indoors: Feb 11 to Feb 25Transplant outside: May 6 to May 20
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 29 to May 13
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 1 to Apr 15Sow outdoors: Mar 25 to Apr 29Plant for fall: Aug 30 to Sep 27
Start indoors: Feb 25 to Mar 11Transplant outside: Mar 25 to Apr 8Sow outdoors: Mar 25 to Apr 8Plant for fall: Aug 16 to Sep 6
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 8 to Apr 22Plant for fall: Jul 19 to Aug 9
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 1 to Apr 15Plant for fall: Jul 19 to Aug 9
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 8 to Apr 22Plant for fall: Jul 19 to Aug 9
Start indoors: Mar 11 to Mar 25Transplant outside: May 13 to May 27Sow outdoors: May 13 to May 27
Start indoors: Mar 11 to Mar 25Transplant outside: Apr 29 to May 13
Sow outdoors: Mar 11 to Apr 1Plant for fall: Aug 2 to Aug 23
Sow outdoors: Mar 11 to Apr 1Plant for fall: Aug 30 to Sep 20
Sow outdoors: Mar 18 to Apr 29Plant for fall: Sep 13 to Oct 4
Start indoors: Mar 25 to Apr 1Transplant outside: May 6 to May 13Sow outdoors: Apr 29 to May 13Plant for fall: Aug 9 to Aug 23
Start indoors: Mar 25 to Apr 1Sow outdoors: Apr 29 to May 13Plant for fall: Aug 16 to Aug 30
Start indoors: Mar 25 to Apr 1Sow outdoors: Apr 29 to May 13
Start indoors: Mar 25 to Apr 1Transplant outside: May 6 to May 20
Sow outdoors: Apr 1 to Apr 29Plant for fall: Aug 2 to Aug 16
Sow outdoors: Apr 1 to Apr 29Plant for fall: Aug 16 to Aug 30
Sow outdoors: Apr 1 to Apr 22
Sow outdoors: Apr 8 to May 6Plant for fall: Aug 16 to Aug 30
Sow outdoors: Apr 8 to Apr 29Plant for fall: Aug 30 to Sep 20
Sow outdoors: Apr 29 to May 20Plant for fall: Aug 9 to Aug 23
Sow outdoors: Apr 29 to May 13
Transplant outside: May 6 to May 27
Plant for fall: Oct 11 to Nov 15
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Merrillville, IN
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 28 – Feb 11 | Mar 25 – Apr 8 | — | — |
| Peppers | Feb 11 – Feb 25 | May 6 – May 20 | — | — |
| Eggplant | Feb 11 – Feb 25 | May 6 – May 20 | — | — |
| Tomatoes | Feb 25 – Mar 11 | Apr 29 – May 13 | — | — |
| Lettuce | Feb 25 – Mar 11 | Apr 1 – Apr 15 | Mar 25 – Apr 29 | Aug 30 – Sep 27 |
| Kale | Feb 25 – Mar 11 | Mar 25 – Apr 8 | Mar 25 – Apr 8 | Aug 16 – Sep 6 |
| Broccoli | Feb 25 – Mar 11 | Apr 8 – Apr 22 | — | Jul 19 – Aug 9 |
| Cabbage | Feb 25 – Mar 11 | Apr 1 – Apr 15 | — | Jul 19 – Aug 9 |
| Cauliflower | Feb 25 – Mar 11 | Apr 8 – Apr 22 | — | Jul 19 – Aug 9 |
| Okra | Mar 11 – Mar 25 | May 13 – May 27 | May 13 – May 27 | — |
| Basil | Mar 11 – Mar 25 | Apr 29 – May 13 | — | — |
| Peas | — | — | Mar 11 – Apr 1 | Aug 2 – Aug 23 |
| Spinach | — | — | Mar 11 – Apr 1 | Aug 30 – Sep 20 |
| Radishes | — | — | Mar 18 – Apr 29 | Sep 13 – Oct 4 |
| Cucumbers | Mar 25 – Apr 1 | May 6 – May 13 | Apr 29 – May 13 | Aug 9 – Aug 23 |
| Zucchini & Summer Squash | Mar 25 – Apr 1 | — | Apr 29 – May 13 | Aug 16 – Aug 30 |
| Winter Squash & Pumpkins | Mar 25 – Apr 1 | — | Apr 29 – May 13 | — |
| Melons & Watermelon | Mar 25 – Apr 1 | May 6 – May 20 | — | — |
| Carrots | — | — | Apr 1 – Apr 29 | Aug 2 – Aug 16 |
| Beets | — | — | Apr 1 – Apr 29 | Aug 16 – Aug 30 |
| Potatoes | — | — | Apr 1 – Apr 22 | — |
| Swiss Chard | — | — | Apr 8 – May 6 | Aug 16 – Aug 30 |
| Cilantro | — | — | Apr 8 – Apr 29 | Aug 30 – Sep 20 |
| Green Beans | — | — | Apr 29 – May 20 | Aug 9 – Aug 23 |
| Sweet Corn | — | — | Apr 29 – May 13 | — |
| Sweet Potatoes | — | May 6 – May 27 | — | — |
| Garlic | — | — | — | Oct 11 – Nov 15 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Valparaiso Wtr Wks, IN weather station, 26 km away (elevation 801 ft (244 m)).
ZIP codes in Merrillville: 46410 46411
Frost dates near Merrillville
- Griffith Apr 23 · Oct 20
- Crown Point Apr 29 · Oct 16
- Hobart Apr 22 · Oct 25
- Schererville Apr 23 · Oct 20
- Gary Apr 22 · Oct 27
- Highland Apr 23 · Oct 20
- Lake Station Apr 22 · Oct 27
- Saint John Apr 23 · Oct 20
Frequently asked questions
When is the last frost in Merrillville, IN?
The median last spring frost in Merrillville, IN is April 22. There is still about a 10% chance of frost after May 6, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Merrillville, IN?
The median first fall frost is October 25, with about a 10% chance of frost before October 12.
How long is the growing season in Merrillville, IN?
About 186 days between the median last spring frost and first fall frost.
What planting zone is Merrillville, IN?
Merrillville, IN is in USDA hardiness zone 6a.