A data center cooling system includes an evaporative cooling system. The evaporative cooling system includes fans configured to circulate outside air at ambient conditions through an entry zone of a data center, and atomizers positioned upstream of the entry zone configured to spray atomized water into the circulating outside air. The atomized water evaporates in an evaporation zone and cools the outside air to produce cooled air, which is directed through racks of computers positioned downstream of the evaporation zone.