Google at the end of every year releases Zeitgeist video, hot trends, popular searches and here is the one for the year 2013.
Zeitgeist Video summarizing World Events in 2013
You’ll find all major trending topics for 2013 on this trends page nicely organized into various categories.
Want to know Top 100 Searches for 2013, checkout this top 100 searches page (Hover over any picture on the page and it’ll turn into a select box, click and learn more about that search keyword with ranking [similar to above image]).
There is even a Google Earth view of Global trends available here. Explore by navigating through countries and cities & you’ll learn about top trending searches by Geo locations.
Overall it is nice to see a collection of all major events in a single place. This is really worth exploring, so check it out.