Trauma centers face novel challenges in resource allocation in an era of cost consciousness and work-hour restrictions. Studies have shown that time of day and day of week affect trauma admission volume; however, these studies were performed in cold climates. Data from 2000 to 2010 at a Level I trauma center were reviewed. Demographic, injury severity, and injury timing from 23,827 trauma patients were analyzed along with their emergency department disposition (operating room, intensive care unit, ward) and final outcome. Nighttime arrivals (NAs) accounted for 56.6 per cent and daytime arrivals accounted for 43.4 per cent of total admissions. The increase in NAs was most pronounced during the period from midnight to 6 am on weekends (P < 0.05). Also, the period from midnight to 6 am on weekends showed a significantly increased proportion of penetrating trauma (P < 0.01). Similarly, there was an increased rate of trauma arrivals needing emergent operative intervention in the period between midnight and 6 am on weekends when compared with any other time period (P < 0.01). In a southern Level I trauma center, patient volume varies nonrandomly with time. Emergent operative intervention is more likely between midnight and 6 am, the peak time for penetrating trauma. Because resident operative experience is maximized at night and on weekends, coverage during these periods should remain a priority for residency programs.