Why Fort Collins is in a drought despite the rain

What a difference 30 miles makes in Colorado's weather.

Fort Collins is exiting the summer stuck in a drought, though skies looked stormy more days than not.

About 30 miles to the southeast, Greeley is happily drought-free. Between May and August, Greeley’s weather station received 103 percent of its normal rainfall. Fort Collins received less than half.

That’s because for months storms have been brewing over the Fort Collins area before moving eastward. The pattern has left Fort Collins parched while Greeley and the Eastern Plains get drenched.

HOT AND DRY: Larimer County issues fire warning until Thursday

“It’s an interesting arrangement, because our late spring and summer precipitation has been very scant,” state climatologist Nolan Doesken said, “but at least half the days since May we’ve had showers and thundershowers forming here, and quite a few days when we’ve had at least a few drops of rain.”

Fort Collins received at least trace precipitation — enough to wet the pavement — about two out of every three days between May and August.

But the rains were generally light, so the U.S. Drought Monitor classified Fort Collins as “abnormally dry” from mid-June through early August, when Fort Collins and Loveland entered “moderate drought” stage.

Doesken has no explanation for the frequent storm pattern that left Fort Collins dry during what should have been some of the wettest months of the year. It’s important to note that we’re in a semi-arid climate, so missing out on a few big storms can have major impact on drought.

About those drought conditions: The U.S Drought Monitor uses five complex measurements to determine whether an area is in a drought, factoring in things like stream flows, soil moisture, temperature and precipitation. Fort Collins hasn't been in a drought since 2013, when the region exited a 15-month stretch of extreme dryness.

NO DROUGHT SINCE 2013: The city officially entered the drought in August

There are four stages of drought, and Fort Collins is now in the mildest stage. Doesken said it’s “not a serious situation” yet because the region had ample water reserves from snowpack this year. Most farmers have had adequate access to irrigation for their fields, so only non-irrigated crop fields and pastureland have taken a hit, Doesken said. People have also probably been using more water on their lawns.

“All it would take is a good upslope fall soaker” — a storm that lands along the eastern slopes of the Rocky Mountains and the plains to the east — “or a couple of fall-early winter wet snows, and the impact would be largely ameliorated,” Doesken said.

Such was the case three years ago this week when in 2013 parts of Fort Collins received 12 inches of rain over several days, and the mountains west of the city even more, causing major damage.

Without adequate fall and winter moisture for the city and mountains, a summer like this sets the stage for something worse, Doesken warned, putting Northern Colorado in dire need of rain come spring.

“All of the sudden things would be quite bad in a hurry, and people will be saying, ‘Where did that come from?’” Doesken said. “Well, it came from the dry summer we had this year.”

Fort Collins precipitation, May to August

May: 1.84 inches (75 percent of 1981-2010 normal)

June: 0.05 inches (2.3 percent of normal)

July: .91 inches (53 percent of normal)

August: .76 inches (48 percent of normal)

Source: National Weather Service