Season’s first freeze likely Saturday

The season's first hard freeze, which seems likely Saturday morning, could nearly denude colorful maple trees.

But coming later than usual, as it is this year, the end of the growing season will have few other ill effects.

At its peak this week in northeast Iowa, fall color will likely be somewhat dimmed by the rapid fall of maple leaves following the first hard freeze, said Bruce Blair, the Iowa Department of Natural Resources forester at the Yellow River State Forest near Harpers Ferry.

'Literally the next day (after a freeze) the maple leaves come raining down,” he said.

The more subtly colored oak leaves, which are more tolerant of the cold, will continue to beautify the bluffs, according to Blair.

Even after the maple leaves have fallen inland, they will persist along the Mississippi River, whose microclimate often protects them from the first freeze, Blair said.

State Climatologist Harry Hillaker said low temperatures Saturday morning will be in the 26-to-27-degree range in much of northeast and Eastern Iowa, constituting a killing frost.

'It's been a pretty late first freeze for most of the state,” he said.

Cedar Rapids, for example, typically records its first frost Oct. 6, while the average first frost date in southeast Iowa is Oct. 17, Hillaker said.

Early frosts can confound apple growers, but David Differding, co-proprietor of Timeless Prairie Orchard east of Quasqueton, said he and his wife, Susan, are not worried about the Saturday morning chill.

'We have a few apples still on the trees, but we are 95 percent picked,” he said.

The remaining unpicked apples have such a high sugar content, he said, that it would take getting down to at least 25 degrees for several hours to damage them.

With their crops almost 100 percent mature, farmers won't mind the freeze, but they could use a rain to settle the dust and reduce the risk of field and combine fires.

Through the first 15 days of October, Hillaker said only one Iowa locale had received more than 0.02 inches of precipitation - Keokuk, with 0.19 inches.

The statewide average temperature in September was 5.3 degrees warmer than normal, and it is running about 3 degrees above normal so far in October, he said.

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