New York, Washington, and the mid-Atlantic region will experience another day of hot and humid weather, with temperatures approaching historical highs. Later, thunderstorms will bring temporary relief. The US National Weather Service predicts that the highest temperature in Central Park in New York will reach 94 degrees Fahrenheit (34 degrees Celsius) on Sunday, slightly lower than the record of 96 degrees Fahrenheit (about 35 degrees Celsius) set in 1988. With increased humidity, the heat index will approach 98 degrees Fahrenheit (about 36 degrees Celsius). In Washington, temperatures may reach 98 degrees Fahrenheit, with a heat index closer to 104 degrees Fahrenheit (about 40 degrees Celsius). Andrew Orrison, a forecaster at the US National Weather Service, said, "Large cities such as Washington, Philadelphia and New York City will face hot weather. It is estimated that the region will be extremely hot today." Over the past week, the East and Midwest regions of the United States have been in a heat wave, causing an increase in energy demand, slower train speeds, and people having to stay indoors.