Last month, we had a week or so of summer-like weather here in Boulder - temperatures in the mid-70s, which felt unseasonably warm for early spring. (The following week it snowed.) But it turns out we weren't alone, here in the foothills of the Rockies. April 2006 was the warmest April in the U.S. since record-keeping began back in 1895, according to the National Oceanic and Atmospheric Administration (NOAA). Across the country, the average temperature was 4.5 degrees warmer than the 20th century average.

The winter of '05-'06 has been much warmer than average, and has brought drought to the already dry Southwest and excessive rain to the wet Northwest.