Summary Information

The State of the Climate Summary Information is a synopsis of the collection of national and global summaries released each month.


National Summary Information - June 2012

U.S. experiences warm and dry June; drought expands to 56% of Lower 48

Nation experiences warmest first-half of year; wildfires claim 1.3 million acres across nation

The average temperature for the contiguous U.S. during June was 71.2°F, which is 2.0°F above the 20th century average. Scorching temperatures during the second half of the month led to at least 170 all-time high temperature records broken or tied. The June temperatures contributed to a record-warm first half of the year and the warmest 12-month period the nation has experienced since recordkeeping began in 1895.

Precipitation totals across the country were mixed during June. The Lower 48, as a whole, experienced its tenth driest June on record, with a nationally-averaged precipitation total of 2.27 inches, 0.62 inch below average. Record and near-record dry conditions were present across the Intermountain West, while Tropical Storm Debby dropped record precipitation across Florida.

Note: The June Monthly Climate Report for the United States has several pages of supplemental information and data regarding some of the exceptional events from the month and season.

Significant U.S. Climate Events for June 2012
Significant climate events for June 2012. Click to enlarge, or click here for the National Overview.

U.S. climate highlights — June

  • Warmer-than-average temperatures were anchored across the Intermountain West and much of the Great Plains during June. Colorado had its warmest June on record, with a statewide temperature 6.4°F above average. Seven additional states in the region had a top ten warm June. 1933 was the warmest June recorded in the contiguous United States.
    June 2012 Statewide Temperature Ranks Map
    June 2012 Statewide Precipitation Ranks Map June 2012 Statewide Temperature (top) and Precipitation (bottom) ranks
  • Cooler-than-average temperatures were present for the Pacific Northwest, where Washington had its seventh coolest June on record. Cooler-than-average conditions were also present for the Southeast, despite record warm temperatures towards the end of the month.
  • Record-breaking temperatures occurred across a large portion of the nation during the second half of June. Over 170 all-time warm temperature records were broken or tied during the month. Temperatures in South Carolina (113°F) and Georgia (112°F) are currently under review by the U.S. State Climate Extremes Committee as possible all-time statewide temperature records.
  • Precipitation patterns were mixed across the country. Drier-than-average conditions were present from the West, through the Plains, into the Ohio Valley and Mid-Atlantic. Wyoming had its driest June on record, with a precipitation total of 0.45 inch, which is 1.27 inches below average. Eleven additional states from Nevada to Kentucky had June precipitation totals ranking among their ten driest.
  • According to the U.S. Drought Monitor, as of July 3, 56.0% of the contiguous U.S. experienced drought conditions, marking the largest percentage of the nation experiencing drought conditions in the 12-year record of the U.S. Drought Monitor. Drought conditions improved across Florida, due to the rains from Tropical Storm Debby. Drought conditions worsened across much of the West, Central Plains, and the Ohio Valley, causing significant impacts on agriculture in those regions.
  • Tropical Storm Debby brought copious precipitation to Florida during June as it slowly traversed the state. Florida's monthly statewide precipitation total of 13.16 inches was 6.17 inches above average, ranking as the wettest June on record for the state. Parts of the Northeast, as well as the Pacific Northwest, were wetter than average. Maine, Oregon, and Washington each had a top ten wet June.
  • Several large wildfires raged across the West in June, destroying hundreds of homes and causing the evacuation of tens of thousands of residences. The very dry, warm, and windy weather created ideal wildfire conditions. Nationwide, wildfires scorched over 1.3 million acres, the second most on record during June.
  • A list of select June temperature and precipitation records can be found here.

U.S. climate highlights — Year-to-Date (January-June)

  • The January-June period was the warmest first half of any year on record for the contiguous United States. The national temperature of 52.9°F was 4.5°F above the 20th century average. Most of the contiguous U.S. was record and near-record warm for the six-month period, except the Pacific Northwest. Twenty-eight states east of the Rockies were record warm and an additional 15 states were top ten warm.
    Year to Date Horserace Graph for Contiguous U.S.
    Year-to-date temperature, by month, for 2012 (black), compared to the five warmest years on record for the contiguous U.S. The 2012 data are still preliminary. Please click for a more thorough explanation.
  • The first six months of 2012 were also drier than average for much of the contiguous U.S., with a nationally-averaged precipitation total 1.62 inches below average. Drier-than-average conditions stretched from the West, through the Central Plains, into the Ohio Valley and Mid-Atlantic. Fourteen states in total had precipitation totals for the six-month period among their ten driest.
  • Wetter-than-average conditions were present for the Northwest and Upper Midwest, where Minnesota, Oregon, and Washington had six-month precipitation totals among their ten wettest.
  • The U.S. Climate Extremes Index (USCEI), an index that tracks the highest and lowest 10 percent of extremes in temperature, precipitation, drought and tropical cyclones across the contiguous U.S., was a record-large 44 percent during the January-June period, over twice the average value. Extremes in warm daytime temperatures (83 percent) and warm nighttime temperatures (70 percent) covered large areas of the nation, contributing to the record high value.

U.S. climate highlights — 12-month period (July 2011-June 2012)

  • The July 2011-June 2012 period was the warmest 12-month period of any 12-months on record for the contiguous U.S., narrowly surpassing the record broken last month for the June 2011-May 2012 period by 0.05°F. The nationally-averaged temperature of 56.0°F was 3.2°F above the long term average. Every state across the contiguous U.S. had warmer than average temperatures for the period, except Washington, which was near normal.
  • During the June 2011-June 2012 period, each of the 13 consecutive months ranked among the warmest third of their historical distribution for the first time in the 1895-present record. The odds of this occurring randomly is 1 in 1,594,323.
  • Ten Warmest 12-month consecutive Periods in U.S. Record
    The ten warmest 12-month periods of the U.S. record. Click to enlarge, or click here for expanded information.