Now that the mercury is rising every day, I've been fielding more and more questions about the "right" 
temperature to store and serve wine. It's good that you're paying attention, too! Because if you just pulled a bottle of white or rose off your wine rack (which, incidentally, is sitting in your un-air-conditioned living room) and then go to sip said wine at room temperature or (just as bad) have over-chilled it, you're probably not enjoying your libation. What's the point of that?!
When it comes to storage:
DON'T leave your wine on a rack in your air conditioned free living room. Sure, short term you may get away with it, but here in Boston our freaky weather has been known to spoil more than a bottle or two after even a 3-4 day heat wave. I don't have a budget that allows me to buy "serious" wines that I should store for several years - though I do have a few. But I also value the cash I do have and try to avoid spoiling any investment.
DO find a spot in your home/apartment where the sun's rays won't find your wine, the temperature stays pretty consistent and won't sit above 75 degrees (MAX). I shoot for any place between 66 and 72 degrees. I have a cellar in my current place, but bought a small wine fridge to avoid spoiling my wine at my last apartment (which could BAKE in the summer). Before that, I didn't even have the space for a fridge and stored my wine under my bed (no kidding); my bedroom was the only place that stayed pretty "mild" during the summer months.
As for serving wine:
DO consider chilling your fruitier, less tannic red wines in the summer. Even about fifteen or twenty minutes in the fridge can get your red wine back down to optimal, serviceable temperature (~65 degrees) on a hot day. I'm not suggesting this as a standard MO in the winter, but room temperature definitely creeps up in the summer months. (Last summer I went out for a fancy meal to celebrate my birthday. I don't know where they were storing the Pinot Noir we ordered, but after they poured me the initial taste, I requested an ice bucket to get it down to a reasonable temperature. The wine really benefited and became a welcome complement to our meal. Poor form on the restaurant's part, but the others in my dinner party were pleased I took the initiative to remedy the situation.) The bottle/glass of red should have just a touch of cool to it.
DO serve your white and rose wines chilled. What does this mean? An hour in the fridge will do the trick. Don't have an hour? Try a bucket of ice with a bit of water to expedite the process. Or, you can take your chances putting the bottle in the freezer in a pinch... The goal is to get the wine down to about 48-58 degrees. (Your fridge should be set for 38 degrees, so you'll want your wine warmer than the bottle of beer you've got in there, too.)
So what's the point of all this, you wonder? It has to do with the science behind wine and your palate to create an optimal balance of fruit, acidity and tannin. Suffice to say, white wines benefit from chilling because the fruit (and it's ripe sweetness) comes forward to complement the acidity they exhibit. You may have noticed that if your glass of white gets too warm, the alcohol becomes more dominant. On the flip side, a white served too cold masks all flavors and aromas. They can taste utterly bland (the same is true for rose - danger!). Sparkling wines additionally benefit from the chill because the carbon dioxide release slows down, allowing the flavors to dance a bit longer via the bubble streams you see in your glass. When red wines are served too warm, the tannin gets exaggerated, the fruit diminishes and the wines taste hot, or alcoholic.
Think you've got the 411 now to beat the heat? What's your experience with wine temperature?