The USDA has upgraded it’s plant hardiness map, which is based on average annual extreme temperatures. Horticulturists and gardeners use the maps as a gauge of what types of plants to grow. Some people think the new data indicates that temperatures are rising, and having visible effects on growing seasons and plant diversity. The USDA is (probably wisely) dodging the climate change aspects, pointing out that the methodologies used weren’t quite the same in the two versions. If you want to have fun, do a google news search for “plant hardiness” and see how different media coverage is of this (Chicago Sun Times, ThinkProgress, MSNBC).

The Washington Post used an interactive slider design on their map to let you flip between views of 1990 and 2012:

You can view static and interactive versions at the USDA site, as well as download the dataset.