From what you have described and where you live (on the coast), it sounds as if the burner orifices and/Or burners may be clogged. You will need to remove the burners to clean them, but this is not a difficult job. Turn off your LP Gas Tank. And after removing the burners, tap each one gently on a firm surface to shake loose any foreign materials from them. Stand each burner on the Orifice end (the open end) and tap them again, gently. Look at where each was tapped to see if any foreign material or rust came out. Also carefully check the flame holes in each burner to make sure they're clear. If clogged use a needle or unfolded paper clip to clear the clogged burner holes. However, never use any thing larger than the existing hole to clean it.

After doing this, check the orifices for each burner. You can find them by looking at the interior part of the front of the grill, where you removed the burners from. If they appear clogged, clean them as you did the burner, but this time use a sewing needle no larger in diameter than the orifice hole. It's best to unscrew the orifices one at a time to do this. Be careful not to drop them.Replace the orifices and burners in reverse of how you removed them. Turn on your grill tank very slowly and then light each burner, one at a time.

If this solved your problem, remember to do it each year.