For an average of seven days per year, maximum temperatures reach more than 100° F in the Southern Plains. By mid-century, the frequency of very hot days (with maximum temperatures above 100°F) could possibly double. By late century, Central Texas north to Kansas may experience an increase of 60-80 more hot days per year. South Texas is projected to see 90-100 additional hot days by the end of the century, according to a range of climate scenarios. The smallest increase in days over 100°F will occur in Kansas, with 40-60 additional hot days. Similar increases are expected in the number of nights with minimum temperatures higher than 80°F in the south. The urban heat island (UHI) effect will cause the rate of temperature rise to be especially large within urban centers.