Steve Gravelle, CR Gazette –
Iowa has missed the extreme weather experienced by much of the country, but this is shaping up to be the warmest year in state history, and it’s getting drier.
Through Tuesday, the statewide average daily temperature for the year of 49.1 degrees is a substantial 6.1 degrees above normal, State Climatologist Harry Hillaker said. The 14.82 inches of precipitation is 2.39 inches less than normal, but “almost all the deficit for the year is because of June,” Hillaker said. “We were almost at normal before June.”
That makes 2012 the 54th-driest year of 140 for which records exist, and the driest since 2006. Statewide averages are based on reports from about 160 reporting sites.
“It’s been very persistently warm, going back to December,” said Hillaker. “If you look at historical records the warmth in the winter typically doesn’t carry through, but this time it did.”
Hillaker doesn’t have records on temperature records set this year. The warmest day so far was Thursday in Keokuk, when it hit 104 degrees.
“Not that many places have reached 100 yet,” Hillaker said. “This week could be changing that.”
Cedar Rapids’ average daily temperature in June was 71.7 degrees, 2.1 degrees warmer than normal. Iowa City’s 73.1-degree average was 1.6 degrees warmer. Add those figures to a warm May and you have a formula for a hot summer, Hillaker said.
“It’s not a guarantee that July would be warmer than normal, but we’re off to a good start,” he said.
Warmer than normal is likely, but Hillaker doesn’t expect many record high temperatures.
“July 1936 was the hottest month ever in Iowa, so it’s going to be hard to get records,” he said. “But it could happen. Dry weather’s something you need to get the temperature records, and certainly we’re very dry right now.”
As crops draw down subsoil moisture, sustained high temperatures become more likely.
“We add a lot of our own moisture from transpiration of crops this time of year, so when that’s gone you get lower humidity and the air warms up,” Hillaker said. “Things could go downhill pretty quickly, and crop-wise they somewhat are already.”
