Cool Change or Hotter Than Ever?

Worldwide, it was the third-warmest June quarter on record, and the warmest ever observed for the world’s oceans, observed author Bob Henson. Some thought it was cooler than usual.  As always, it’s critical to look beyond a single cool spell—or even a cool season over an entire region—to see what’s happening to our planet’s climate in full.

Bob Henson in UCAR Communications  (21 September 2009):  

If you’re a gardener in New England, you might remember the wet, cool summer of 2009 for its tomatoes and potatoes, ravaged by the earliest and most widespread “late blight” on record. If you’re from south Texas, you were probably just trying to keep green things alive in heat and drought on par with the Dust Bowl’s worst.

Such were the contrasts of the season across the United States. Rumor has it that it was a cool, damp summer—and indeed it was, if you happened to live in the populous Midwest and Northeast. It was the coolest July on record in five states: Ohio, Illinois, Indiana, Pennsylvania, and West Virginia.  For the country as a whole, meteorological summer (June through August) came in as the 30th coolest in the last 115 years.

Some folks took the mild summer in the central and northeast U.S. as a sign that global climate change has been overblown. But, when you step back and look at the June-through-August period for Earth as a whole, central North America stands out as one of the few areas where temperatures were below average.

In the graphic (go to website to view) from NOAA’s National Climatic Data Center, most other parts of the globe are swathed in above-average red, with places like Winnipeg and Chicago enveloped in a small oasis of below-average blue.

Worldwide, it was the third-warmest June/July/August on record, and the warmest ever observed for the world’s oceans, according to NCDC. Let’s look at some of the numbers, which I’ll give in the temperature scale in which they were reported, followed by a conversion to the other scale (Fahrenheit or Celsius).

The frequent lake breezes that kept Chicago air-conditioned this summer, and the delightful absence of hazy heat in New York’s Central Park, where it never topped 92°F (33.3°C), sounded pleasant enough. Yet the records being set on the other side of the country were not only more impressive but more dangerous. 

In July, at least three major cities—Austin, San Antonio, and Phoenix—had their hottest single months ever recorded. So did Death Valley, California, where 22 days reached or topped 120°F (48.9°C). And Seattle smashed its all-time daily heat record, hitting 103°F (39.5°C), an event extensively chronicled by University of Washington professor Cliff Mass in his weather blog.

Australia was unusually hot too—especially noteworthy given that it was still winter on that side of the globe.  As noted by the Bureau of Meteorology, August was the most anomalously warm month in the continent’s history (bureau statement, PDF), running an impressive 3.20°C (5.76°F) above average.  Many parts of Australia topped 35°C (95°F) at least once in August.  Brisbane hit highs in midwinter that it hadn’t reached even in the preceding summer.

As always, it’s critical to look beyond a single cool spell—or even a cool season over an entire region—to see what’s happening to our planet’s climate in full.

About Bob Henson

Edit the UCAR Quarterly. The Quarterly brings news from UCAR and its member institutions to the research community.

Edit Highlights, the magazine-style summary of UCAR/NCAR/UOP research and support activitiespublished every two years.

Help write news releases and assist with media inquiries, particularly those involving severe weather (tornadoes, hurricanes, etc.).

My background

On July 20, 1960, I was born in the Great Plains metropolis of Oklahoma City, my hometown through high school. Surrounded by wild weather, I grew up fascinated by it. My bachelor’s degree at Rice University featured an interdisciplinary major in meteorology and psychology. I went to graduate school in both meteorology and journalism at the University of Oklahoma. For my M.A. thesis in journalism, I studied the broadcasting of severe weather warnings on local television.

I’ve been at UCAR since 1989, covering the wide range of research and related activities conducted by NCAR, UOP, and UCAR’s members and affiliates.

I enjoy freelance writing on a variety of topics. I am a contributing editor of Weatherwise magazine and was a frequent correspondent for the The Weather Notebook radio show. I’ve written Television Weathercasting: A History (McFarland, 1990), The Rough Guide to Weather (Rough Guides/Penguin, 2002), and The Rough Guide to Climate Change (Penguin, 2006).

Bicycling: I’ve done several tours of 200-800 miles and spend a lot of my transportation time on two wheels.

Storm photography: Over the past 25 years, while on research experiments and personal travel, I’ve seen around 30 tornadoes and a vast array of severe thunderstorms. To the right is a photograph of a rotating LP (low-precipitation) supercell near Wray, Colorado, on June 2, 1999, with a small rain core impersonating a tornado.

About UCAR

The University Corporation for Atmospheric Research promotes partnership in a collaborative community dedicated to understanding the atmosphere—the air around us—and the interconnected processes that make up the Earth system, from the ocean floor to the Sun’s core.

The National Center for Atmospheric Research and UCAR’s community programs provide research, observing and computing facilities, and a variety of services for the atmospheric and Earth sciences community. 

NCAR and the UCAR Community Programs are managed by UCAR, a nonprofit consortium of research universities, on behalf of the National Science Foundation and the university community.

Source: www.ucar.edu