The objective of this research is to estimate the value of solar irradiance in the province of Lambayeque using the empirical model of Bristow-Campbell, taking as data the recorded values of maximum and minimum daily temperatures provided by the National Service of Meteorology and Hydrology (SENAMHI)-Dirección Zonal 2, Lambayeque, period 2014-2019. This will allow the design of solar systems tailored to the electrical or heating requirements in a reliable, safe and economical way. The solar energy available at a site of interest is a fundamental physical quantity for the design of photovoltaic systems and solar collectors that allow generating electricity and heat respectively. However, the measurement of this physical quantity is scarce or nonexistent, resorting then to empirical methods to obtain estimated values of solar irradiance, considering as input data the meteorological variables measured in the area of interest such as sunshine hours, maximum and minimum temperatures, relative humidity, precipitation, wind speed and direction, etc.