Summit County Citizens Voice

2011 will probably end up being one of the top10 wettest years on record in Summit County.

Weather year showing a 60 percent moisture surplus so far

By Summit Voice

SUMMIT COUNTY — After going gangbusters in July, rainfall tapered off in August, dropping to below average for only the second time since the beginning of the water year (water-watchers use Oct. 1 as the start of the hydrological year). June 2011 was the only other month with below average precipitation.

Breckenridge National Weather Service observer Rick Bly said he recorded 1.88 inches of August rain, compared to the long-term average total of 2.26 inches. That brings to annual total precipitation at the Breckenridge site to 30.11 inches, a full 60 percent above average. 2011 will likely go down in the books as one of the top-five wettest years.

July’s precipitation total in Breckenridge ended up at 7.15 inches, the second-wettest July on record and the third-wettest month in the record books. Almost half that rain fell on July 18 in a single storm, as slow-moving thunderstorms drenched the area with more than 3 inches. The all-time wettest month on record in Breckenridge was February 1899, with 8.4 inches of water equivalent that came in the form of snow during a winter of historic snowfalls.

Looking ahead, Sept is the second-driest month of the year (after June) with an average of 1.47 inches of precipitation. An average September brings 4 inches of snow. The wettest September on record was in 1961, with 3.74 inches of precipitation — and that year also brought record-breaking September snow, with 53 inches of the white stuff piling up.

In Dillon, where Denver Water officials measure precipitation and temperatures on a daily basis, August rainfall was slightly above average for the month, at 2.08 inches. Average for the month is 1.77 inches.

The monthly temperatures readings are probably skewed by four days of missing data when the thermometer wasn’t working. Leaving out those days, the average daily maximum temperature was 74.7 degrees, a couple of degrees above the historic average, which is 72.5 degrees — almost exactly the same average high as in San Francisco (72 degrees). The average daily low in August was 38.1, also a couple of degrees above the historic average of 36 degrees.

In September, the daily average maximum temperature drops down to 66.2 degrees and daily average minimum temperature drops back down below freezing, to 28.7 degrees. July and August are the only two months of the year with average minimum temps above freezing. On average, 1.7 inches of snow falls in Dillon during September.

The warmest September reading on record in Dillon was 84 degrees, on Sept. 15, 1954. The coldest reading on record was a chilly 4 degrees, on Sept. 21, 1924.

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