Record Rainfall, Widespread Warmth Highlight September Climate Report

September was the sixth warmest and 12th wettest of the past 119 years nationally, according to the National Climatic Data Center (NCDC), which releases its State of the Climate report every month.
The federal government’s climate agency released its analysis of September temperature and precipitation data for the U.S. on Monday, more than a week later than usual, after the partial government shutdown prevented the information from being released on time.

Temperatures Compared to Average

Widespread Warmth

The warmth was widespread, with 26 of the contiguous 48 states logging above-average September temperatures. Most of these states were in the western two-thirds of the country. Seven states – Idaho, Montana, Wyoming, Colorado, North and South Dakota, and Nebraska – registered a top-10 warmest September on record.
Only four states – New York, Pennsylvania, New Jersey, and Maryland – were labeled cooler than average. The Empire State had the coolest state-by-state ranking, logging its 33rd coolest September of the past 119 years.
The NCDC defines above-average temperatures and precipitation as readings placing in the top one-third of the historical record for a given area, and below-average temperatures and precipitation as those placing in the bottom one-third.

Precipitation Compared to Average

Record Rainfall

September’s historic Colorado flood disaster was reflected in the official data, with the Centennial State logging by far its wettest September on record. The statewide average of 4.09 inches was 40 percent wetter than Colorado’s previous September record of 2.93 inches set in 1961.
In fact, only two other months in Colorado recordkeeping have been wetter – April 1900 (5.51 inches) and April 1942 (4.20 inches).
The state record was driven by extreme rainfall in mid-September, particularly over the northern part of Colorado's Front Range. Some locations near Boulder picked up well over a foot of rain in just five days, leading to destructive flash floods.
An unusually early bout of heavy rainfall also pushed Washington and Oregon to their wettest Septembers on record. Oregon crushed its 1986 record by a margin of 30 percent, while Washington was about 4 percent wetter than its previous 1959 record.
Seattle received 6.17 inches of rain on the month, eclipsing a 35-year-old record. It was also the wettest September on record in Portland, Ore., where 5.62 inches of rain last month crushed the old September record of 4.30 inches set in 1986.
Such heavy rainfall is more typical of November, December, and January in the Pacific Northwest.


http://www.weather.com/news/record-rainfall-widespread-warmth-highlight-september-climate-report-20131023