When to plant in Highland, IN
USDA Zone 6aEverything below — frost dates, hardiness zone, and what to plant when in Highland, Indiana — is derived from the closest NOAA station with complete climate normals.
Highland's nearest full-normals station sits about 19 km out, so treat these as a close estimate — local microclimate can nudge your first and last frost. Zone 6a means Highland sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
PARK FOREST · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Highland’s own odds, recorded at PARK FOREST.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 24 | May 5 | Apr 20 | Sep 27 | Oct 10 | Oct 22 |
| 32°F | May 11 | Apr 23 | Apr 9 | Oct 6 | Oct 20 | Nov 1 |
| 28°F | Apr 27 | Apr 12 | Mar 30 | Oct 18 | Oct 30 | Nov 15 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Highland, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 32 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Highland planting FAQ
When is the last spring frost in Highland, IN?
Highland's average last spring frost falls near April 23 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Highland, IN?
The first fall frost in Highland typically arrives around October 20 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Highland in?
Highland is in USDA hardiness zone 6a. In zone 6a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Highland?
There are roughly 180 frost-free days in Highland (a moderate growing season), running from the average last frost around April 23 to the first fall frost near October 20.
When should I plant tomatoes in Highland?
In Highland, start tomato seeds indoors around February 26–March 12, then transplant seedlings outdoors around April 30 once the danger of frost has passed.
Never miss a window in Highland
An email when it’s time to start seeds, transplant, and sow — timed to Highland’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Griffith · 4 km
- Munster · 4 km
- Dyer · 7 km
- Schererville · 7 km
- Lansing · 8 km
- Hammond · 9 km
- Calumet City · 9 km
- Gary · 10 km
Frost dates recorded at PARK FOREST, 19 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Highland, IN — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00116616. Retrieved from https://blissgarden.com/indiana/highland.