Chris Izworski

Michigan Soil Temperature: When Is It Warm Enough to Plant?

Today's reading at your nearest MSU weather station, a forecast checked against it, and its past springs.

Typical spring

Turn on JavaScript to see today's soil temperature near you.

The page reads MSU Enviroweather's station measurements and a forecast in your browser.

See what to plant this weekThis station on MSU Enviroweather

Which seeds?

Planting temperature

The soil 2 inches down at this station

Solid green: measured by MSU. Dashed rust: the forecast, adjusted to match the station. Shaded: the middle half of past springs at this station, with its middle line dashed.

    How this works, and what it cannot tell you
    • Measured: the soil temperature 2 inches down at the nearest MSU Enviroweather station (the Michigan Automated Weather Network). Each day's figure is the average of that day's low and high. Your own bed can run a few degrees warmer or colder than the station, with different soil, shade, mulch or a raised bed.
    • Forecast: the Open-Meteo weather model's soil temperature at about 2.4 inches (6 cm), for the station's location. Models run warm or cold in soil, so the page shifts the whole forecast by the average gap between model and station over the last 7 days, and says how big that shift was. This site has not measured how accurate the adjusted forecast is; treat dates more than a week out as rough.
    • The rule: MSU gives the temperatures, not a rule for a single day. This page counts the soil as warm enough from the first day its daily average stays at 40°F or more (or above 60°F) for the rest of the data: the rest of the forecast for this year, or through June 30 for past springs. A warm afternoon that is followed by a cold week does not count.
    • Past springs: the same station's measured springs, 2016 to 2026 where it has them. Springs with more than 12 missing days, or a gap of more than a week, are left out, and readings more than 12°F away from all nearby stations are treated as sensor faults.
    • Frost: warm soil is one of MSU's two conditions for warm-season crops. The other is that the danger of frost is past, which this site reads as the nearest frost station's cautious date (only 1 spring in 4 still freezes after it). Frost dates for 78 stations.
    • Everything runs in your browser. Nothing you type is sent anywhere except the station's location, to the two data services.
    MSU's two numbers: beets, carrots, radishes and turnips germinate once the soil at planting depth reaches 40°F, and beans, squash, cucumbers and other warm-season seed need it above 60°F. At most of MSU's stations the soil 2 inches down settles at 40°F or warmer between late March and mid-April, and above 60°F between mid-May and early June. At any one station the date moves by about four weeks from spring to spring, so check this year's reading above.

    Why soil temperature, not the calendar

    Seeds respond to the soil they sit in, and soil warms more slowly than air in spring. MSU Extension's planting guide puts it in two numbers. Seeds of beets, carrots, radishes and turnips "will germinate at a minimum of 40°F." Warm-season seed, like beans, squash and cucumbers, "will not germinate well unless the soil temperature at planting depth exceeds 60°F." A thermometer pushed to planting depth in the morning answers the question for your own bed. This page answers it for the nearest station, which has measured its soil every day for years, and turns a forecast into a date.

    When does Michigan's soil usually warm up?

    Across the 91 MSU stations with at least five measured springs from 2016 to 2026, the middle date for the soil 2 inches down to stay at 40°F or warmer runs from March 19 at South Haven to April 24 at McMillan near Newberry, with most stations between March 27 and April 13. Staying above 60°F comes about seven weeks later: from May 14 at Cassopolis to June 16 at Hawks, McBain and Petoskey, with most between May 21 and June 8. The year matters as much as the place. Across all stations, the middle 40°F date came as early as March 23 (2021) and as late as April 23 (2020), and the 60°F date ranged from May 15 (2024) to June 14 (2019). At a typical station, its earliest and latest springs were about four weeks apart.

    Questions

    What depth should I check soil temperature at?

    MSU's numbers are for the soil at planting depth. Most seeds go in less than 2 inches deep, so this page uses the station's 2-inch sensor. The 4-inch reading is listed too; it lags the 2-inch one in spring.

    Why is the station reading different from my thermometer?

    The station sits in open, level ground with its own soil and cover. Dark soil, a south slope, a raised bed or plastic mulch warm faster; shade, wet clay or a thick mulch warm slower. Use the station as the regional trend and your thermometer as the final word.

    Does warm soil mean it is safe to plant tomatoes and beans?

    Not on its own. MSU also says warm-season crops cannot go out until the danger of frost is past. When you pick the 60°F seeds, this page shows the later of the two dates. What to Plant Now in Michigan puts both together for every crop.

    Michigan garden tools by Chris Izworski

    Sources: soil temperature measured by MSU Enviroweather (Michigan Automated Weather Network), read live and, for past springs, downloaded on October 24, 2026. Forecast: Open-Meteo, licensed CC BY 4.0. Planting temperatures: How to Plant Vegetables, MSU Extension (updated April 29, 2009). Frost dates: Michigan State Climatologist Office via MSU Extension.
    Built by Chris Izworski, writer, technologist and gardener in Bay City, Michigan.