Updated daily

Iowa soil temperature

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Estimated 2–4 inch soil temperature, statewide average . Based on NOAA weather stations near representative Iowa locations.

Check your exact ZIP

Enter your ZIP code for the estimated soil temperature near you, plus what it means for seasonal pre-emergent timing. Use the separate tools below for other lawn tasks.

What this soil temperature means for your Iowa lawn

The Iowa reading loads from the latest daily data. Use the value above or enter your ZIP code for a location-specific recommendation.

Estimated soil temperature at Iowa locations

ZIP code Est. soil temp Data through
50309 — Loading…
52240 — Loading…
50010 — Loading…
52801 — Loading…

Values load from each ZIP's nearest NOAA station in the current R2 snapshot. Enter your own ZIP above for a reading closer to home.

A Continental Climate Means Volatile Soil Temperatures

Iowa sits in the heart of the continent with no ocean or Great Lake to steady its weather, so soil temperature here moves in bigger swings than almost anywhere east of it. An April warm surge can push lawn-depth soil up 10 degrees in a week, and the next cold front can take half of it back. That volatility is exactly why Iowa State University Extension and Outreach tells both farmers and homeowners to trust soil readings over calendar dates.

The reliable pattern underneath the noise is a northwest-to-southeast gradient. Southeast Iowa around Burlington and Keokuk warms first each spring, while the northwest corner around Spencer and Sheldon runs seven to ten days behind. Des Moines and central Iowa typically hold a sustained 55°F at 2-4 inches in late April.

The Most-Watched Soil Number in the State

No state watches soil temperature more closely than Iowa, because corn planting hinges on the 50°F threshold at seed depth. When that number arrives and the forecast holds, planters roll on millions of acres within days. Home lawns ride the same physics: the soil that is ready for corn is within about a week of the readings that drive spring lawn treatments and garden planting.

The gardener's ladder in Iowa follows familiar rungs: peas and lettuce around 45°F in early-to-mid April, sweet corn and beans at 50-55°F in late April to early May, and tomatoes and peppers once soil holds 60°F, usually mid-May in central Iowa. Checking the soil temperature in Iowa today before planting saves more seed than any other single habit.

Wet Prairie Soils Warm on Their Own Schedule

Iowa's deep, dark prairie-derived soils are superb at absorbing solar energy, but they also hold enormous amounts of water. In a wet spring, especially on the poorly drained flats of the Des Moines Lobe in north-central Iowa, saturated soil can sit stubbornly cold for a week or more after air temperatures turn warm, because so much incoming heat goes into the water instead of the soil.

Drainage therefore rewrites the local map: a tiled field or a well-drained lawn on a slope crosses thresholds days ahead of a low, wet yard nearby. Use the statewide estimate for the trend, and if your lawn stays soggy after rain, assume your actual soil temperature runs a few degrees behind the number shown.

How Iowa compares to the rest of the country

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Estimated 2–4 inch soil temperature by state . Tap a state for its detailed page.

About Iowa lawns

Iowa is in USDA Hardiness Zones 4b-5b, with a cool-season lawn climate. Common grass types include Kentucky Bluegrass, Tall Fescue, Perennial Ryegrass, Fine Fescue.

These estimates are modeled from air temperature (about ±5°F at 2–4 inch depth — methodology). For local agronomic guidance, see the Iowa State University Extension and Outreach.

Common Iowa soil temperature questions

What is the current soil temperature in Iowa?

This page shows a statewide estimated 2–4 inch soil temperature for Iowa, recomputed daily from NOAA weather station records, plus per-ZIP estimates for representative Iowa locations. Enter your ZIP code for the reading nearest you.

At what soil temperature should I apply pre-emergent in Iowa?

Apply pre-emergent when Iowa soil temperatures approach 55°F at a 2–4 inch depth in spring — crabgrass germinates as soil holds 55°F and above. In Iowa that typically happens late april to early may.

What soil temperature does grass seed need in Iowa?

Soil temperature alone does not set a seeding date. Seeding timing for common Iowa lawns (Kentucky Bluegrass, Tall Fescue, Perennial Ryegrass, Fine Fescue) follows published regional calendars for each grass type; the overseeding tool shows any calendar available for your ZIP, with this estimate as context.

How accurate is this Iowa soil temperature estimate?

It is modeled from air temperatures with a published lag model, not measured by in-ground sensors, and is typically within about ±5°F at 2–4 inch depth. Shade, moisture, and snow cover shift real readings; for precise numbers use a soil thermometer or Iowa State University Extension and Outreach resources.

When does Iowa soil reach 50 degrees for planting?

In a typical spring, southeast Iowa reaches a sustained 50°F at 4 inches in mid-April, central Iowa in the third week of April, and the northwest corner near the end of the month. Iowa State University Extension and Outreach publishes county-level soil temperature maps each spring precisely because this crossing sets the corn planting calendar.

Why do wet springs keep Iowa soil cold?

Water has a far higher heat capacity than mineral soil, so a saturated profile needs several times more energy to warm one degree than a dry one. Evaporation from wet ground also carries heat away. After a rainy stretch, Iowa soil can lag air temperatures by a week or more, with poorly drained north-central flats affected most.

How different is soil temperature between northwest and southeast Iowa?

Usually seven to ten days of spring timing, or roughly 4-6°F on a given April day. Southeast Iowa sits lower, farther south, and in a slightly milder zone, so Burlington-area lawns cross 55°F while Spencer and Sheldon are still in the 40s. The gap narrows by summer, when the whole state converges in the 70s.

Soil temperature in nearby states

AlaskaConnecticutDelawareIllinoisIndiana

View the national soil temperature map