This is an original data set where rainwater samples were collected with a rain bucked prepared to avoid isotopic fractionation following the indication from the International Atomic Energy Agency (IAEA). We use a rainfall collector containing mineral oil, and samples from the collector were extracted within a maximum of 24 hours from the rain event and sometimes soon after precipitation ceased. Isotope analyses were carried with laser spectroscopy using working standards calibrated against the accepted Vienna Standard Meteoric Oceanic Water (VSMOW) for international reference and comparison. We analyzed the isotopic composition of 138 rain samples collected a permanent location with the aid of a rain bucket containing mineral oil. Samples were collected soon after every rainfall event between July 2014 and December 2021. Rainfall was collected at one permanent location at a residential area in Ciudad Obregon, Sonora Mexico within the Cajeme municipality (27.511850, -109.956316) in the transition zone between the urban and agricultural area in the northeastern edge of the city.