During a preliminary study that supported the Joint Urban 2003 field experiment (JU2003), fifteen Portable Weather Information Display Systems (PWIDS) stations were installed in the Central Business District (CBD) of Oklahoma City. The PWIDS sites continuously measured wind speed, wind direction, temperature, and relative humidity, from July 2002 through May 2003 while fixed to traffic lights and/or mounted atop rooftops. During JU2003, the PWIDS were redeployed within the CBD to compliment the vast array of additional meteorological measurement systems. In addition, a network of 33 HOBO temperature data loggers were deployed at a height of 2 meters across transects centered on the CBD of Oklahoma City during JU2003.

Using temperature observations collected by the PWIDS and HOBO networks within Oklahoma City and similar observations at Oklahoma Mesonet sites in the surrounding rural terrain, composite analyses of the urban heat island (UHI) were created for (a) both 2 and 9 meters during the JU2003 experiment and (b) at 9 meters from July 2002 to May 2003. The composite results demonstrated a mean UHI of 1-2 Celcius at the 9 meter height which persisted regardless of time of year. However, the observations collected at 2 meters during JU2003 revealed a strong UHI signal during the overnight period and a weak urban cool island (UCI) signal during the daylight period. As such, temperatures within the CBD of Oklahoma City were, on average, slightly cooler than the surrounding rural observations during daylight periods. Further, for those sites with co-located temperature observations at 2 and 9 meters, the strength of the nocturnal inversion was significantly greater at the rural Mesonet sites than within the CBD. Finally, the variability of the sites within the CBD revealed strong relationships consistent with diurnal solar radiation trends while similar results were not discovered at the rural Mesonet sites.