The HiTemp project (High Density Measurements within the Urban Environment), operated networks of meteorological sensors installed within the Birmingham conurbaton: Approximately 250 low-cost, battery-powered WiFi air temperature sensors and 30 full automatic weather stations (AWS), measuring temperature, precipitation, relative humidity, wind speed and direction, pressure, solar radiation. The design is based around a nested network of sensors:

Network 1 (coarse array): 30 AWS will be sited in primary electricity sub-stations (average spacing of 3km)
Network 2 (wide array): 150 air temperature sensors located on schools (one in every medium super output area (MSOA), or areas containing a population of 7,200)
Network 3 (fine array): 100 air temperature sensors located on lampposts in the CBD (50/km2)