Zacklabe is a site, created by the climate scientist and National Oceanic and Atmospheric Administration researcher, Zachary Labe, that has many great visualizations of data regarding climate change, especially about the Arctic and Antarctic. It gathers its data from scientific observations, which are cited. You can access the visualizations following this link. Here are the visualizations, with many graphics for each entry.

Arctic Climate Seasonality and Variability
Arctic Sea Ice Extent and Concentration
Arctic Sea Ice Volume and Thickness
Arctic Temperatures
Antarctic Sea Ice Extent and Concentration
Climate Change Indicators
Climate model projections compared to observations in the Arctic
Global Sea Ice Extent and Concentration
Polar Climate Change Figures

Note: I briefly created a similar topic, but it was only about a single link from here. I deleted because I realized it's much better to create a thread about the site in general.