Dev Nyogi, the state climatologist, and Ken Scheerigna, his assistant, can't tell you when it will freeze at your farm in 2011. However, using data from the past several decades collected in Indian, they can give you an idea of what to expect as fall unfolds after one of the wildest spring and summer combinations in Indiana history.
Where you live will determine when you see the first freeze, officials say. The date for the first freeze tends to be later in the year as you move south in Indiana, but there are exceptions, based on local topography and microclimates, all of which affect weather occurrences such as frost. For example, east-central Indiana typically sees a killing frost or freeze before some other parts of the state, even some farther south, due to the general topography of the area.
Here are some observations to keep in mind, based on history.
For most of Indiana the first freeze (32 degrees F) has come during the five days of Oct. 12 to 16. The average date is two weeks later along the Ohio River in the south, where it is naturally warmer, and along Lake Michigan in the north, where the lake is warmer than the land during this time of the year.
It's a near certainty that most of Indiana will see its first fall freeze by Oct. 31. The exact percentage is a 90% chance.
Last year, freeze dates got an early start, and extended out over a month. The date of first fall freeze in 2010 in Indiana ranged from October 4 to November 6.
For some farmers who were delayed in planting corn and soybeans, despite the hot summer, there's a risk that crops won't mature before an early killing freeze.
Frost, which can occur above 32 degrees, can damage leaves of immature corn and result in some yield loss. But the loss would not be as large as that from plants exposed to temperatures of 28 degrees or lower for several hours, notes Bob Nielsen, Purdue University corn specialist.
Based on Sept 18 estimates, about 39% of the Indiana soybean crop should be mature by today. Shaun Casteel, Purdue University Extension soybean specialist, says those fields should be ready to harvest in 5 to 10 days, given good weather conditions. A few early-planted fields were harvested in mid-to-late September.That leaves 60% of the soybean crop in Indiana that won't be ready for harvest until mid-October, Casteel says. The catch is that weathermen are predicting a shift to a much colder, wetter weather pattern sometime in the last half of fall. The timing of harvest could become interesting for soybeans, especially those planted later last spring.