Seven weeks with barely an inch of rain will do it.
Omaha is officially back in drought, according to the National Drought Mitigation Center.
For farmers and gardeners, the news affirms what they've already known: The soil is much too dry, even though about a half-inch of rain fell in Omaha this week.
Also now considered in drought: all of Douglas and Sarpy Counties, most of eastern Cass County and a wide swath of western Iowa.
Brian Fuchs, a climatologist with the drought center, said the drought designation is unlikely to be short-lived.
More than one good rain is needed to get out of drought. Omaha is short about 6 inches of rain over the past 12 months, he said.
“If August is a wet month and we start digging into our deficits, then drought could retreat,” he said.
The drought designation was removed from Omaha in early June, after being in place for nearly a year.
Al Dutcher, Nebraska state climatologist, said significantly above-normal rainfall will be needed for at least a couple of weeks for Omaha to become drought-free.
Although that type of rain is tough to come by, it's not impossible given current storm patterns, Dutcher said. Lately, slow-moving storms have inundated affected areas.
Earlier this week a long corridor of northeast Nebraska received about 2 inches of rain.
During the first seven days of August, record rainfall — 3.16 inches — fell in North Platte, according to the National Weather Service. The previous Aug. 1 to Aug. 7 high for North Platte, 2.63 inches, was set in 1906, according to the weather service.
Although conditions have deteriorated in much of eastern Nebraska and western Iowa, most of the rest of Nebraska has seen steady improvement.
Southern, southeastern, northern and western Nebraska have all benefited from rains.
For the first time in more than a year, none of western Nebraska is in the worst category of drought, although a small area along the Kansas border remains mired in exceptional drought.
Dutcher said western Nebraska has benefited from the active monsoon season in the southwestern United States. That season tends to peak in July.
He said cooler-than-normal weather across the region has eased the sting of this year's drought. Unlike last year, which was Nebraska's hottest and driest on record, this year has been cool enough that irrigated plants can metabolize and reproduce without being affected by heat stress.
The area of the landscape that still requires special attention is the trees, said Mary Anna Anderson, a horticulturist with University of Nebraska-Lincoln Extension in Douglas and Sarpy Counties.
Trees require deep, infrequent watering. Homeowners often don't realize that trees derive little value from — and, indeed, are sometimes harmed by — the frequent watering needed by lawns.