FiveThirtyEight, sometimes rendered as 538, is an American website that focuses on opinion poll analysis, politics, economics, and sports blogging.

Take-A-Sweater? uses historical weather records to compare currently predicted temperatures with what actually happened under similar conditions in the past.

Metaculus is a community dedicated to generating accurate predictions about future real-world events by aggregating the collective wisdom, insight, and intelligence of its participants.

Users can track their predictions, earn points and powers, and hone their forecasting skills.