An estimation of climatological fields of incident solar energy in Tamaulipas State, northeastern Mexico, is presented. Monthly mean evolution of solar energy in 7 automatic meteorological stations distributed along the State shows that the maximum values generally exceed 500 +/- 200 W m(-2) during fall-winter (Nov-Feb), and 700 +/- 200 W m(-2) during spring-summer (May-Aug). An empirical model, which estimates the solar energy as function of other climatic variables (minimum temperature, maximum temperature, evaporation, and precipitation) recorded in 165 climatological conventional stations, is used to extend the climatological solar-energy estimate in the study area. The mean values of both measured and estimated solar energy are objectively mapped to fill the observation gaps and reduce the noise associated with inhomogeneous statistics and estimation errors. The highest values of solar energy (similar to 6.7 kW h m(-2) during the summer and similar to 4.0 kW h m(-2) during the winter) are observed in the highlands, southwestern part of the State, whereas the lowest values (similar to 5.7 kW h m(-2) during the summer and similar to 2.8 kW h m(-2) during the winter) are observed in the south-central part of the State. (C) 2013 Elsevier Ltd. All rights reserved.