While many programs take a break in the summer in Italy, there are some that continue, and these programs are generally quite good and are useful in helping to improve your listening Italian skills. One of my favorite shows is Passaggio a Nord-Ovest -- you can watch the episodes through the PC through Rai's web site or, if you're lucky enough to be in Italy, it's on TV on Saturdays at 5:45 PM.
The host of the program is Alberto Angela, a well-known journalist and television personality who often hosts television programs on archaeology and culture (along with his father -- Alberto also holds a degree in Natural Science from La Sapienza). In this program, Alberto Angela crosses the globe visiting cultural sites as well as visiting some unique sites in Italy. There's also a very informative show on the giant squid, its history and research into this unique and amazing creature. The programs aren't always about history and archaeology but a true exploration of our planet into areas and sites that often don't receive a lot of attention.
I've watched about a dozen episodes - they last between 5 minutes to as long as 15 minutes. Alberto Angela is easy to understand, speaks well, and brings a passion and love for what he does -- not only can you listen and improve your Italian, but you can also learn something, too!