The National WWII Museum
Weather changes all the time. Climate can change too, but more slowly. To know if climate is changing, you need to measure weather from lots of places over a long period of time and compare all that information together.
This site hosts data from classrooms across the country. Students in these places are collecting the weather from their site on a day, and comparing it to the weather in the same spot 75 years ago. Over time this will give us a picture of what the climate is like now in all these places, and how it might have changed over the last century. This is real Citizen Science, with students and teachers collecting and analyzing data in concert with scientists and talking together about methods and meaning of the results.