Rainlog.org is a network of your neighbors that report rain totals in their backyards. You can also sign up to report rain totals. To see how much rain fell in your area, simply zoom in and out on the Google map for rain total reports nearby. You can also sign up for the Rain Mapper e-mail. This e-mail will report how much rain fell in your backyard by triangulating the rain reports from your neighbors.
Pima County Regional Flood Control ALERT Systemis a network of weather and streamflow sensors in the Tucson metropolitan area. These sensors measure rain totals with some measuring how much water is flowing in area washes. Plus every hour, this Precipitation Report is updated. Many neighborhoods and towns in and around the city of Tucson have multiple sensors.
CoCoRaHSstands for Community Collaborative Rain, Hail, and Snow Network. Like Rainlog.org, this network gathers data from volunteers.