July Weather a Record-Breaker

This weather this July was a record-breaker in many ways, both in the U.S. and across the globe, according to a new report from the National Climatic Data Center (NCDC).

Released this week, "Climate of 2007 - July in Historical Perspective" summarizes a month's worth of extreme weather in many areas. They include record high temperatures in much of the western U.S., moderate to exceptional drought in nearly half the U.S., above-average temperatures over much of the globe's land areas and near-record global combined land-sea temperatures.

"Below-average rainfall, combined with scorching temperatures, helped put 46 percent of the contiguous U.S. in some stage of drought by the end of July," the report stated. "The global average temperature was the seventh warmest on record for July, and the presence of cooler-than-average waters in the central and eastern equatorial Pacific reflected the possible development of a La Niña episode."

A La Niña cycle, in which sea surface temperatures in the central and eastern tropical Pacific are cooler than normal, often leads to drier-than-normal conditions in the American Southwest, Central Plains and the Southeast. During La Niña, winters in the Southeast tend to be warmer than normal while the Northwest experiences colder-than-normal winters.

Among the weather records set last month:

* Idaho, Montana and Wyoming all experienced the warmest July on record;

* Boise, Idaho, had an average temperature of 98.6 degrees Fahrenheit (37 degrees Celsius), more than 9 degrees Fahrenheit (5 degrees Celsius) above average;

* Missoula, Montana, reported 11 days of triple-digit temperatures, nearly double the previous record of 6 days;

* For the period from January through July, the average combined land and sea surface temperature around the globe was the second warmest on record. For the month of July alone, it was the seventh warmest.