We've vacationed in Bali during July, and found it rather comfortable. Warm days (mid 80s), mild nights (75) and a near constant breeze. We stayed in Nusa Dua, if that makes a difference.

I'm not accustomed to heat, given I live on the cool California coast. We would have had no problems sleeping with doors and windows open, and no A/C.

The numbers may say it's humid, but I didn't find it bothersome in the least.