Fixed stations versus automobile transects were compared for a 27-day period between July and November 2001 to investigate urban, residential, and rural temperatures and dew points post-sundown for a sub-region in the metropolitan area of Phoenix, Arizona. Temperature and dew point differences were determined among urban (urb), residential (res), and rural (rur) from the fixed sites (fix) and the mobile transect route (tran). On average, transects revealed a mean ΔT_{(urb-rur)tran} of 7.3°C (standard deviation, σ, of 2.02°C) and ΔT_{(res-rur)tran} of 3°C (σ = 1.09°C); whereas the fixed site results were ΔT_(urb-rur)fix of 4.8°C (σ = 2.78°C) and ΔT_(res-rur)fix of 2.3°C (σ = 1.81°C). Comparisons of dew points for ΔT_{d(urb-rur)tran} and ΔT_{d(res-rur)tran} were −3.21°C (σ = 4.56°C) and −1.0°C (σ = 1.44°C), respectively; whereas the ΔT_{d(urb-rur)fix} and ΔT_{d(res-rur)fix} values averaged 1.27°C (σ = 2.85°C) and −0.10°C (σ = 2.75°C), respectively. The use of a Soil-Adjusted Vegetation Index (SAVI) assists in interpreting the overall results of the differences among sites and highlights the important role of surface vegetation and moisture in reducing temperatures in this desert urban setting. An ongoing mobile climate sampling system is planned within the Central Arizona-Phoenix Long-Term Ecological Research program (CAP LTER) to maintain seasonal and long-term climate sampling in order to determine local details linking urban ecology and land cover change to climate change in this metropolitan region.