To help you make good corn planting and nitrogen application decisions, you need to know the soil temperature at the 4-inch depth. If you want to keep up to date on soil temperatures in your area, you can do that by going online to Iowa State University's web site.

Related: For Planting Corn, Soil Temperature Of 50 Degrees Is Magic Number

Iowa 4 inch soil temperature maps for the last three days are published by ISU Extension and the College of Agriculture and Life Sciences.

Soil temperatures at 4-inch depth around Iowa are kept updated on the weather page on Iowa State University's website.

Keep track of the weather outlook for Iowa this spring
People involved in agriculture who are interested in weather can watch two online sites maintained by the National Weather Service for clues on weather trends.

The National Weather Service 30-day forecast offers a glimpse at precipitation and temperature outlooks for Iowa in the spring.

The NWS 90-day outlook is a longer term forecast that covers temperatures and precipitation for spring.

Some time ago, Elwynn Taylor, ISU Extension climatologist, said that what happens with the weather in Arkansas during March and April tends to be what happens with the weather in Iowa during the planting season.

To see what kind of weather has been occurring in Arkansas and thus what kind of weather pattern may be heading to Iowa during planting, visit the NOAA website then click on the "Water" tab, then the "Precipitation" tab.

Below the map that will appear, you then need to select "Last 30 Days," "Departure from Normal," and "Arkansas."

This story first appeared on April 1, 2010. It was updated on April 1, 2015.