Is a red sky at night a good sign?

I've always found the 'red sky in morning, sailors take warning; red sky at night, sailor's delight.' to be fairly consistent.   The sky last night was fiery, but today is overcast and gray.  Hmmmmm.....  If it's going to be gray, then I want it to rain hard!  We need it after a hot, dry summer.   But just gray alone won't do it for me.  (The really dramatic red sky images were ruined by utility poles and wires.)