Traditionally the major risk environment for transmission of dengue virus has been assumed to be households. In Mexico, dengue outbreaks continue year after year despite intense control efforts. Nonresidential sites (public and private spaces) infested with Aedes aegypti (L.) were evaluated. In total, 141 nonresidential sites were sampled for the presence of potential and active oviposition sites and adult mosquitoes. Eighty percent of the sites were oviposition sites; Ae. aegypti adults were recovered at 94.7% of nonresidential sites. Most female Ae. aegypti, 21.6 and 10.4, were at schools and recreational sites, respectively. Chi-squared indicated no significant differences in the dengue vector to categories of sample sites (X² = 17.76, df = 9, P = 0.38). Indoor-use patterns of adult mosquitoes indicated bathrooms and classrooms were preferred resting sites. Reverse transcription polymerase chain reaction (RT-PCR) assay did not identify dengue virus nucleic acids from a group of 221 pools containing 1,521 female Ae. aegypti. Daytime human activities; e.g., school and work, synchronize with the bimodal biting pattern of Ae. aegypti, increasing the chance of transferring dengue virus.