With just nine days left in July, rainfall in Steamboat Springs is lagging more than 1.3 inches behind the average for the month. And with every day that passes, grasshoppers in the area are becoming more resistant to disease.
But that doesn't mean residents will see anything like the unforgettable grasshopper plagues of 2002 and 2003.
"What I'm seeing is isolated spots where there are increasing numbers of grasshoppers," CSU Cooperative Extension Agent C.J. Mucklow said. "But we're nowhere near a widespread infestation."
Steamboat had recorded just 0.22 inches of rain through July 21 compared to the month's average of 1.54 inches, local weather observer Art Judson said.
The perfect storm of back-to-back drought seasons in '02 and '03 produced high grasshopper egg production and low juvenile mortality rates that led to an infestation of biblical proportions.
"It was awful," Mucklow said. "We searched (historical records) and couldn't find any record of any infestation here that was that widespread."
Grasshoppers are susceptible to diseases associated with high moisture, and they are most susceptible as juveniles, Mucklow said. A dry spell like Routt County is enduring increases the chances that grasshoppers in the tall grass of July will live to lay viable eggs in late August.
A hot August would further that possibility, and a warm, dry June in 2009 could lead to a big year for the insects. Still, Mucklow would be surprised to see anything next summer that comes close to 2002 and 2003, when grasshopper counts soared as high as 100 to 200 per square yard.
Anything more than 15 grasshoppers per square yard is considered an infestation. Mucklow said a U.S. Department of Agriculture employee is conducting a spot census of grasshopper concentrations across the county, but he hasn't heard any specific results.
"Any place I've been, I haven't met the official count of 15," Mucklow said. "I checked with (Blaine Tucker at) Mountain Air Spray, and no one has asked for spraying. We've recently had telephone reports that they've got them bad in Big Valley Ranch (near Colorado Highway 131 and Routt County Road 35 south of Steamboat), and a couple people on the west side of Sleeping Giant haven't actually counted but said they have more than the threshold."
Mucklow said the scarce precipitation during the latter part of June and continuing into July has robbed the valley of the potential for near record dry land hay production.
"We haven't had significant precipitation in my view, since June 12 when it snowed," Mucklow said.
After more than 3 inches of precipitation in May, the Yampa Valley was sitting pretty going into the summer. But low June temperatures didn't promote the growth of meadow hay, making that crop just average to good.
"The irrigated hay looks very good," Mucklow said.
Judson said his weather station between downtown and Mount Werner received 0.01 inch on July 2, 0.1 inches on July 3, 0.05 on July 7 and 0.06 inch on Monday.
"Average July precipitation is the second-lowest (of the year)," Judson said. "June averages 1.53, and that is the lowest. August averages 1.63, September 1.8 and October 1.91."
Judson said January has the highest average precipitation of the year, at 2.47 inches at his station.
This summer's lack of rainfall has been offset to a degree by abundant flows in the Yampa River. Tuesday's stream flow at the Fifth Street Bridge was 233 cubic feet per second, according to the U.S. Geological Service. That compares to the historic median of 177 cfs for July 22.