National Geographic

VOICES Voices Icon Ideas and Insight From Explorers

Menu

Hot Enough For You? Here’s Why

Photo by Luis Marden

 

For Americans who are sweating it out around the country, the news won’t come as much of a surprise:  the first five months of 2012 have been the hottest on record in the continental United States.  This past June 164 all-time heat records were broken or tied, and July is off to a sweltering start.  What’s causing the latest heat wave?

According to Jeff Weber, a scientist at the University Corporation for Atmospheric Research in Boulder, a high pressure system (also known as a heat ridge) is to blame.  The system, which originated in the western part of the U.S., has now settled over the Midwest and southeastern part of the country.  Thanks to a slowdown in the North Atlantic Oscillation – a climate pattern that normally carries air from west to east – this system has come to a standstill, keeping the searing heat from moving on out over the ocean.

The western part of the country could be in for some relief soon as the North American monsoon season gets underway, but the National Weather Service is predicting even more hotter-than-average days ahead, which means we’ll all have to work a little harder at staying cool.

For all the latest science news, check out the National Geographic’s twice-weekly news rundown, EarthCurrent.