
Here's the chart of U.S. temperatures published by NASA in 1999. It shows the highest temperatures actually occurred in the 1930's, followed by a cooling trend ramping downward to the year 2000:
The authenticity of this chart is not in question. It is published by James Hansen on NASA's website. On that page, Hansen even wrote, "Empirical evidence does not lend much support to the notion that climate is headed precipitately toward more extreme heat and drought."