July 2013: Earth's 6th Warmest July on Record

July 2013 was the globe's 6th warmest July since records began in 1880, according to NOAA's National Climatic Data Center (NCDC). NASA rated it the 10th warmest July on record. The year-to-date period of January - July has been the 6th warmest such period on record. July 2013 global land temperatures were the 8th warmest on record, and global ocean temperatures were the 5th warmest on record. July 2013 was the 341st consecutive month with global temperatures warmer than the 20th century average. Global satellite-measured temperatures in July 2013 for the lowest 8 km of the atmosphere were 10th or 8th warmest in the 35-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH), respectively. Wunderground's weather historian, Christopher C. Burt, has a comprehensive post on the notable weather events of July 2013 in his July 2013 Global Weather Extremes Summary. The big stories that he highlights are the extraordinary heat waves in the central portion of Russia’s Arctic region and in eastern China. Both heat waves were unprecedented for their respective locations. Extreme heat has killed at least 40 people in China since July 1. Also, Greenland measured its hottest temperature on record July 30th when the mercury hit 25.9°C (78.6°F) at Maniitoq Mittarfia during an unusually strong local wind event called a foehn.


Figure 1. Departure of temperature from average for July 2013, the 6th warmest July for the globe since record keeping began in 1880. Most of the world's land surfaces were warmer than average during July. The United Kingdom and Australia had their 3rd warmest July temperatures on record, and South Korea and New Zealand, their 4th warmest July. Parts of the central and southeastern United States, small regions across northern Canada, eastern Greenland, and parts of Mongolia and eastern Russia were cooler than average. Far northwestern Canada and part of the eastern United States were much cooler than their long-term averages. Image credit: National Climatic Data Center (NCDC) .

Six billion-dollar weather disasters in July
Six billion-dollar weather disasters hit Earth during July. The most damaging of these were in China: the on-going drought in Central and Eastern China that has cost $6 billion this year, and significant flooding across nearly every section of China between the 7th and 17th, which left 305 people dead or missing, and cost $4.5 billion. The world-wide tally of billion-dollar weather disasters so far in 2013 is nineteen, and the U.S. total is five, according to the July 2013 Catastrophe Report from insurance broker Aon Benfield:

1) Flooding, Central Europe, 5/30 - 6/6, $22 billion
2) Drought, Brazil, 1/1 - 5/31, $8.3 billion
3) Drought, Central and Eastern China, 1/1 - 7/31, $6.0 billion
4) Flooding, Calgary, Alberta Canada, 6/19 - 6/24, $5.3 billion
5) Tornado, Moore, OK, and associated U.S. severe weather, 5/18 - 5/22, $4.5 billion
5) Flooding, China, 7/7 - 7/17, $4.5 billion
7) Flooding, Indonesia, 1/20 - 1/27, $3.31 billion
8) Flooding, Australia, 1/21 - 1/30, $2.5 billion
9) Tornadoes and severe weather, U.S., 5/26 - 6/2, $2 billion
9) Severe weather, Midwest U.S., 3/18 - 3/20, $2 billion
11) Winter weather, Europe, 3/12 - 3/31, $1.8 billion
12) Drought, New Zealand, 1/1 - 5/10, $1.6 billion
12) Severe weather, U.S., 4/7 - 4/11, $1.6 billion
14) Flooding, Toronto, Canada, 7/8, $1.45 billion
15) Flooding, China, 6/29 - 7/3, $1.4 billion
15) Flooding, China, 7/21 - 7/25, $1.4 billion
17) Flooding, Argentina, 4/2 - 4/4, $1.3 billion
18) Flooding, India and Nepal, 6/14 - 6/18, $1.1 billion
19) Winter weather, Plains, Midwest, Northeast U.S., 2/24 - 2/27, $1.0 billion


Figure 2. Heavy flood waters sweep through Beichuan in southwest China's Sichuan province on July 9, 2013. Rainfall amounts as high as 1,150 millimeters (45.3 inches) of rain fell in the Dujiangyan region, triggering Sichuan Province's worst floods in at least 50 years. Flooding in China from July 7 - 17, 2013 cost at least $4.5 billion. Image credit: AFP/Getty Images.

Neutral El Niño conditions continue in the equatorial Pacific
For the 16th month in row, neutral El Niño conditions existed in the equatorial Pacific during July 2013. NOAA's Climate Prediction Center (CPC) expects neutral El Niño conditions to last though the fall, and the large majority of the El Niño models also predict that neutral conditions will last through the fall of 2013. Temperatures in the equatorial Eastern Pacific need to be 0.5°C below average or cooler for three consecutive months for a La Niña episode to be declared; sea surface temperatures were 0.4°C below average as of August 19, and have been +0.1 to -0.4°C from average since April 1, 2013.

Arctic sea ice falls to 5th lowest July extent on record
Arctic sea ice extent during July was 5th lowest in the 35-year satellite record, according to the National Snow and Ice Data Center (NSIDC). Arctic sea ice extent maintained a steady, near-average pace of retreat through the first half of August, making it very unlikely that the record low minimum extent observed in September 2012 will be surpassed this year. Nevertheless, there are extensive areas of low-concentration ice, even in regions close to the North Pole.

Quiet in the Atlantic
There are no tropical disturbances of note in the Atlantic today. None of the computer models is calling for tropical cyclone formation in the Atlantic during the coming week. In the Eastern Pacific, there is a tropical disturbance (94E) about 600 miles southwest of Manzanillo, Mexico that is growing more organized. In their 8 am EDT Wednesday Tropical Weather Outlook, NHC gave the disturbance a 60% of developing by Friday, and a 90% chance of developing by Monday. The GFS and European models predict that 94E will become Tropical Storm Ivo and pass close to the coast of Baja California over the weekend.


Video 1. Most spectacular weather video of July: a tornado in Milan, Italy on July 29 hurls huge amounts of debris against the office building the video was taken from. The photographer is lucky the building's windows didn't shatter and seriously injure him. Jason Samenow at the Capital Weather Gang has more videos and details on the event.

Jeff Masters