Zionsville, Indiana
Zionsville soil temperature
How warm the ground is about two inches (6 cm) down — the seedbed gardeners plant into — for Zionsville today, against the year’s normal range, with a day-by-day table and a look at the week ahead.
Soil right now in Zionsville
Tuesday, June 30, 2026Modeled for the center of town, not a probe in your yard — a sunny raised bed runs warmer, a shaded or clay spot cooler.
How the soil is trending
The week ahead from the forecast, and how the soil looked behind us — each compared with today’s reading.
| When | Low | Soil (2 in) | High | vs. today |
|---|---|---|---|---|
| Today Tue, Jun 30 · forecast | 74°F | 80°F | 86°F | — |
| Tomorrow Wed, Jul 1 · forecast | 74°F | 80°F | 87°F | 0°F |
| In 3 days Fri, Jul 3 · forecast | 75°F | 81°F | 87°F | +1°F |
| In a week Tue, Jul 7 · forecast | 70°F | 77°F | 84°F | −3°F |
| When | Low | Soil (2 in) | High | vs. today |
|---|---|---|---|---|
| Today Tue, Jun 30 · forecast | 74°F | 80°F | 86°F | — |
| Yesterday Mon, Jun 29 · forecast | 73°F | 78°F | 83°F | −2°F |
| A week ago Tue, Jun 23 | 59°F | 67°F | 76°F | −12°F |
| A month ago Sat, May 30 | 60°F | 69°F | 78°F | −11°F |
| Three months ago Mon, Mar 30 | 50°F | 58°F | 68°F | −21°F |
| A year ago Mon, Jun 30 | 72°F | 79°F | 87°F | −1°F |
2026 soil temperature
The brick line is this year’s reading; the green band is the typical range for each date over 1991–2020; the dashed end is the past few days and the week-ahead forecast. Hover or drag across it to read any day.
The year so far
The turning points of the 2026 soil year — the seasonal lows and highs, and the spring dates the ground first warmed through the planting thresholds.
When the soil is warm enough to plant
Read against the seedbed (~2 in) reading above. “Plant at” is the practical floor; “best” is the optimum germination range.
| Crop | Plant at | Best | Notes |
|---|---|---|---|
| Peas | 40°F | 40–75°F | Germinates from 40°F; hardy — weeks before the last frost. |
| Lettuce | 40°F | 40–80°F | Germinates as low as 35°F; semi-hardy. |
| Spinach | 45°F | 45–75°F | Germinates as low as 35°F; hardy. |
| Potatoes | 45°F | — | Seed pieces; hardy. |
| Onions | 50°F | 50–95°F | Sets or seed; hardy. |
| Sweet corn | 60°F | 70–86°F | Floor ~50°F, but wait for 60°F to dodge seed rot. |
| Beans | 60°F | 60–85°F | Tender — after the last frost. |
| Tomatoes | 60°F | 60–85°F | Seed floor 50°F; set transplants out when nights hold 60–65°F. |
| Peppers | 60°F | 65–95°F | Very tender. |
| Cucumbers, squash & melons | 60°F | 70–95°F | Very tender. |
Lawn timing
| Crabgrass pre-emergent | Down before the soil reaches the upper 50s°F — crabgrass starts germinating at 57–64°F an inch down (Purdue). In central Indiana that’s usually early-to-mid April. Because this page’s 2-inch reading runs a touch cooler than that 1-inch number, don’t wait for it to hit the upper 50s — lean on the calendar and the forsythia bloom, or you’ll be late. |
|---|---|
| Preventive grub control | Calendar, not soil temp: early-to-mid July, around egg hatch (Purdue E-271); water in about ½ inch. |
| Fall lawn seeding | Best from about late August through mid-September — the soil is still in the upper 60s to mid-70s°F for fast germination, with enough warm weeks left to root before the late-October frost. By October it has cooled into the 50s and there’s little time left to establish. |
Germination temperatures from Purdue Extension HO-186-W; crabgrass timing from Purdue Turfgrass Science; grubs from Purdue E-271; zone from the 2023 USDA map; frost dates from NWS Indianapolis normals.
| Date | Low | Soil (2 in) | High | Change | vs. normal |
|---|---|---|---|---|---|
| Sun 1 | 31°F | 31°F | 32°F | +1°F | −1°F |
| Mon 2 | 30°F | 31°F | 31°F | −1°F | −1°F |
| Tue 3 | 30°F | 31°F | 32°F | 0°F | −1°F |
| Wed 4 | 22°F | 29°F | 32°F | −1°F | −2°F |
| Thu 5 | 20°F | 23°F | 27°F | −6°F | −8°F |
| Fri 6 | 22°F | 27°F | 31°F | +4°F | −5°F |
| Sat 7 | 21°F | 28°F | 32°F | +2°F | −4°F |
| Sun 8 | 24°F | 28°F | 31°F | −1°F | −5°F |
| Mon 9 | 22°F | 27°F | 32°F | 0°F | −5°F |
| Tue 10 | 30°F | 32°F | 35°F | +4°F | −1°F |
| Wed 11 | 32°F | 33°F | 33°F | +1°F | 0°F |
| Thu 12 | 32°F | 32°F | 33°F | 0°F | 0°F |
| Fri 13 | 29°F | 32°F | 33°F | −1°F | 0°F |
| Sat 14 | 32°F | 33°F | 36°F | +1°F | +1°F |
| Sun 15 | 34°F | 37°F | 44°F | +4°F | +4°F |
| Mon 16 | 33°F | 38°F | 47°F | +1°F | +4°F |
| Tue 17 | 34°F | 40°F | 46°F | +2°F | +7°F |
| Wed 18 | 42°F | 49°F | 57°F | +9°F | +15°F |
| Thu 19 | 44°F | 50°F | 55°F | +1°F | +16°F |
| Fri 20 | 37°F | 44°F | 53°F | −6°F | +9°F |
| Sat 21 | 33°F | 34°F | 37°F | −10°F | −1°F |
| Sun 22 | 29°F | 32°F | 34°F | −3°F | −4°F |
| Mon 23 | 26°F | 29°F | 31°F | −3°F | −7°F |
| Tue 24 | 25°F | 29°F | 31°F | 0°F | −7°F |
| Wed 25 | 31°F | 37°F | 45°F | +9°F | +1°F |
| Thu 26 | 33°F | 36°F | 44°F | −1°F | +1°F |
| Fri 27 | 33°F | 39°F | 49°F | +3°F | +3°F |
| Sat 28 | 38°F | 45°F | 53°F | +6°F | +9°F |
“vs. normal” is how far that day ran above or below the 1991–2020 average for the date. Rows marked fc are forecast.
Common questions
What is the soil temperature in Zionsville right now?
As of June 30, the soil about two inches down at the Zionsville town center is around 80°F — about 5° above the 74°F that's normal for the date. The shallow reading swings with the weather day to day; it’s a modeled estimate from Open-Meteo for the center of town, updated daily — not a probe in your yard.
When is it warm enough to plant tomatoes in Zionsville?
At about 80°F, the soil is warm enough for tomatoes. Most gardeners set transplants out after the soil is reliably in the 60s and the last spring frost — around April 15 here — has passed. Peppers, beans, cucumbers, squash, and melons want about 60°F too, so it pays to wait for warm-season crops rather than rush them into cold ground.
When should I apply crabgrass preventer in Zionsville?
The 2-inch reading is already about 80°F, so that window has likely passed for the year. Crabgrass starts to germinate when the soil reaches 57–64°F about an inch down (Purdue), so the preventer needs to be down a little before that — in central Indiana, usually early-to-mid April. Because this page’s two-inch reading runs a touch cooler than that one-inch measurement, don’t wait for the number here to reach the upper 50s, or you’ll be late; lean on the early-April calendar and the forsythia “hurry up” bloom. Once the soil holds about 73°F, crabgrass is germinating in earnest and the window has closed.
How is the soil temperature measured, and how accurate is it?
These are modeled readings, not a probe in your yard. They come from Open-Meteo, which estimates soil temperature for the Zionsville town center from weather-model data, updated daily; the history back to 1991 is ECMWF’s ERA5-Land reanalysis. Your own bed can sit a few degrees off — a south-facing raised bed warms faster, while a shaded or heavy-clay spot runs cooler and wetter — so treat this as a regional reading to plan around, and confirm a borderline planting with a soil thermometer in the bed you’re about to seed.
What is a safe planting date for the garden in Zionsville?
The average last spring freeze at the nearest long-record station is April 15, and the average first fall freeze is October 26 — about a 194-day growing season (NWS Indianapolis, 1991–2020). Hardy crops like spinach, peas, onions, and lettuce go in weeks before that last-frost date; tender crops like tomatoes, beans, and squash wait until after it. Zionsville is a little more rural and north of the airport station, so its last frost can run a few days later — a useful margin for tender transplants.
What hardiness zone is Zionsville in?
Zionsville (ZIP 46077, Boone County) is USDA Zone 6a on the 2023 Plant Hardiness Zone Map, meaning the coldest night of an average winter falls between −10 and −5°F. The zone tells you which perennials, shrubs, and trees survive the winter here; the soil-temperature readings above tell you when in the year it’s warm enough to plant.
How this is built
These are modeled estimates for the center of Zionsville (about 39.951° N, 86.262° W), about two inches down — not a probe in your own yard, which can run several degrees off depending on sun, slope, mulch, and soil. History back to 1991 is ECMWF’s ERA5-Land reanalysis; the most recent few days and the week-ahead outlook are the Open-Meteo forecast model (the dashed part of the line). No modeled depth exactly matches the 2-inch or 4-inch garden standards, so we report the ~2-inch seedbed band and label it plainly rather than imply a precision it doesn’t have. Updated daily.
Weather data by Open-Meteo.com, used under CC BY 4.0.