Also, look at different classes of connectors. In pro-speaker land, you'll often find a thing called "SpeakON" (http://en.wikipedia.org/wiki/Speakon_connector). While not explicitly weatherized, these connectors are meant to survive all kinds of abuse and are also going to do a much better job than traditional connectors at keeping the water out.

(And, the connectors are all of $3/each. I recently rebuilt a bunch of cables like this for my daughter's elementary school...)