Heatwave in the United States

Heatwave in the United States

Sweltering temperatures lingered over the southwestern United States though much of July 2005. By July 23, the heat had caused 21 deaths in Arizona, where temperatures soared over 45 degrees Celsius (115 F) for several days in a row. The high temperatures in the west are reflected in this image, which shows land surface temperatures in the United States between July 12 and July 19, 2005. The image was created from data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite.

Because the land retains heat better than the air, the temperatures are slightly warmer than the air temperatures recorded by weather thermometers. In the west, cool patches of purple trace out the contours of mountain peaks where elevation decreases the temperature. Western valleys, however, are scorching hot, topping 60 degrees Celsius (140 F).

Though monsoon rains could bring relief to Arizona, high temperatures are forecast for the rest of the United States for the rest of the summer. The National Oceanic and Atmospheric Administration’s Climate Prediction Center expects temperatures across the United States to remain warmer than average through October.

NASA image created by Jesse Allen, Earth Observatory, using data provided courtesy of Dr. Z. Wan, MODIS Land Science Team.