sultriness

from WordNet (r) 3.0 (2006)

sultriness
    n 1: oppressively hot and humid weather
    2: the quality of expressing or arousing sexual desire; "the
       sultriness of her look was unmistakable"; "the sultriness of
       lust was in the air"

from The Collaborative International Dictionary of English v.0.48

Sultriness \Sul"tri*ness\, n.
   The quality or state of being sultry.
   [1913 Webster]