I was in Varadero for work last June/July and the weather was good. Like Cheese said, high 20's to low 30's. But the notable thing was that every single day in the early evening, a big thunderstorm would roll in and pretty much flood the streets in a half hour period. Then the clouds would scurry off and your day would carry on.
I stayed at the Villa Tortuga which is not a luxurious place by any means, but I thought its location was excellent. Right in town so you could walk down the street and check out the various bars and restaurants. The resort food was mostly bad but the restaurants nearby were actually really good.
Cigars are everywhere. When you go to one of the streetside bars you may be asked, in order, if you want 1) a mojito, as each bar claims they make the best one in Cuba, 2) a cigar, and 3) a girl. If you're a couple, maybe they won't ask you #3...
One of the Canadians that worked down there had a connection to get cheap cigars so they can be gotten cheaper than what the shops will offer. I think we got two boxes for 60 pesos... not sure of the possible repercussions of getting caught in this situation!
I'll echo the posters that said the Cuban people are excellent. Very friendly and they love their Canadian visitors.
Edit - oh yeah, the beach was easily the most beautiful I have ever seen. Clean warm water, soft white sand. The only problem is keeping your beer cold because of the shortage of ice in Cuba.