On the basis of the meteorological data in the low-emission representative concentration pathway (RCP) 4.5 and high-emission RCP8.5 scenarios from the regional climate model output for 2021–2099, spatiotemporal changes in mean annual temperature, annual precipitation, and the average daily radiation in Northeast China in the future were analyzed using statistical methods in this study. The results are as follows. (1) The mean annual temperatures in the RCP4.5 and RCP8.5 scenarios are 6.26 and 7.36 °C, respectively, both showing a trend of significant increase. The increase rate in the RCP8.5 scenario is higher; there are more years with abrupt change in the RCP4.5 scenario. The temperature in the RCP4.5 scenario has two periods of 2 and 4 years, whereas that in the RCP8.5 scenario is composed of two periods that fail the significance test. The empirical orthogonal functions (EOFs) of the first feature vector fields in the RCP4.5 and RCP8.5 scenarios are 90.26 and 96.61%, respectively. The change types are consistent, and the sensitive areas of variation mainly appear in the western and northern regions. (2) The annual precipitation in the RCP4.5 and RCP8.5 scenarios are 959.95 and 949.02 mm, respectively, showing a nonsignificant increase trend. Among them, abrupt changes in annual precipitation are more frequent in the RCP8.5 scenario, and there are 2 and 6 years in the RCP4.5 scenario and 3 and 5 years in the RCP8.5 scenario. The EOFs of the first three feature vectors are 65.66 and 66.77%. (3) The average daily radiation are 8.56 and 8.80 MJ/(m2·d) in the RCP4.5 and RCP8.5 scenarios, respectively, both showing a significant increase trend, with a higher increase rate in the RCP8.5 scenario. The abrupt changes in the two scenarios show a large difference, and radiation in the RCP4.5 scenario has a 4-year period and that in the RCP8.5 scenario has a 3-year period. The EOFs of the first three feature vectors are 66.47 and 81.38% in the RCP4.5 and RCP8.5 scenarios, respectively.