The results of investigations of an annual variation and interannual variability of the outgoing longwave radiation (OLR) intensity performed with the RegCM4 regional climate model are presented. Modelling data was obtained for the Altai region in 20032012 for the A1B evolution scenario of the global climate system. An accuracy of the discussed results is verified by comparing the simulated data with the AIRS/AMSU-Aqua hyperspectral suite archive data that accumulated in the ASU space monitoring center. It is shown that the simulation results satisfactorily reproduce the satellite data. Analysis of the annual variation and interannual variability of the OLR intensity shows that the maximum difference between model and satellite data does not exceed  15 − 20 W/m2. The rate of change of OLR intensity anomalies for the Altai region for the above presented period is −0.16 W/m²/10 yr and −0.14 W/m²/10 yr according to the RegCM4 model and the AIRS/AMSU hyperspectral suite respectively. In the conclusion, the possibility of using the RegCM4 regional climate model to estimate the OLR anomalies intensity changes is demonstrated.