July 2015 warmer and wetter than average for the US
The Northwest and Southeast were warm while the central U.S. was cool. Record precipitation in parts of California did little to improve long-term drought.
The July contiguous U.S. average temperature was 73.9°F, 0.2°F above the 20th century average and ranked near the middle in the 121-year period of record. The average contiguous U.S. temperature for January-July was 53.0°F, 1.7°F above the 20th century average, and the 10th warmest year-to-date on record.
The July precipitation total for the contiguous U.S. was 3.16 inches, 0.38 inch above average. This was the 14th wettest July on record, and marked the fourth consecutive month of above-average precipitation for the Lower 48. Above average precipitation was observed across much of the West, Great Plains, and Ohio Valley. Below-average precipitation was observed in parts of the Southern Plains, Southeast, and Northwest.
Above-average temperatures were observed in Alaska and the Northwest—Washington had its fourth warmest July. The Southeast was also warmer than average where Florida, Louisiana, Mississippi, and South Carolina were all much warmer than average. Louisiana had its third warmest July on record. No state was record warm. Below-average temperatures stretched from the Great Basin, through the Central Rockies, and into the Central Plains and Midwest. Above-average precipitation across these regions was associated with suppressed daytime temperatures. No state had July temperatures that were much cooler than average.
In the West, California, Nevada and New Mexico were much wetter than average. California had its second wettest July on record with 0.64 inch of precipitation, 0.46 inch above average. This is the dry season for California—even small precipitation totals can cause large departures from average compared to history. In mid-July, the remnants of Hurricane Dolores impacted the state with record precipitation observed in Los Angeles and San Diego. Flash flooding caused significant impacts, including destroying a busy bridge on Interstate Highway 10. The precipitation did little to improve long-term drought conditions or improve wildfire conditions in northern parts of the state. Above-average precipitation was also observed in the Ohio Valley, where four states were much wetter than average. Kentucky had its wettest July on record with 8.99 inches of precipitation, 4.65 inches above average. This bested the previous record of 8.25 inches set in 1910. This is the second consecutive month with record wetness in parts of the Ohio Valley. Below-average precipitation was observed across parts of the Northwest, with worsening drought conditions in the region. Below-average precipitation was also observed across parts of the Great Lakes and Southeast. Louisiana had its ninth driest July on record. According to the August 4 U.S. Drought Monitor report, 27.1 percent of the contiguous U.S. was in drought, up slightly since the end of June. Drought conditions improved across parts of the Southwest and Northeast. In the Southeast, drought improvement and degradation were mixed, with only scattered precipitation impacting the region. Drought conditions remain dire across California, with 46.0 percent of the state experiencing the worst category of drought (D4, exceptional).