It shouldn't hurt it. I've always used 10w30 in my vehicles. I think the 5w30 is just a lighter oil that you can use when the weather dips below a certain temp (I think when it's colder than 40 degrees) but I've never bothered even in my cavalier 4 banger. Have had any problems turning over when trying to start when cold out.
They call for 5w-30 when they're new, but once you get up to 75,000 miles or so then switch to 10w-30, since the engine is worn, it needs a little thicker oil. I ran 20w-50 in my 91 Firebird with 140k on it and it did great.