We've gone the first or second week of December the past 6 years. It really varies. 1998, 1999 & 2001 were beautiful, highs around 80, no rain. 2000 was cold, highs in the low 60's most of the week. 2002 & 2003 were a mix, some cold (as low as 50's during the day), some warm (mid 70's). The only real rain we hit was 2002, we had hard rain for 24 hours twice. It's a great time to go though, just be prepared. Last year I brought a light winter coat and gloves, I was glad I had them on a couple nights.