The aim of this study was to assess the impact of weather factors on the yield of selected cereals in the context of ongoing climate change. The study used variables specifying factors such as temperature, precipitation, as well as control variables, which were the share of medium and heavy soils in a given province and the consumption of mineral fertilizers in kg of NPK/ha. The dependent variables were yields of selected cereals. Data were collected from databases of the Polish Institute of Meteorology and Water Management National Research Institute (IMGW PIB), Poland Statistics (GUS), and Institute of Soil Science and Plant Cultivation State Research Institute (IUNG PIB). The meteorological data came from 157 meteorological stations located in 14 provinces. Estimation was carried out for the 2013–2020 period. The study used the panel regression method. For all the models estimated, there was a significant effect of the number of days with precipitation on yields. While regularly occurring, moderate rainfall is undoubtedly favorable, large amounts of rainfall can adversely affect yields. Another statistically significant climatic factor is temperature during spring and summer, with moderate temperatures being the most favorable for yields. Changes in temperature affected yield changes in individual cereals with varying intensity, with the strongest effect recorded for wheat. On the basis of the research carried out, a conclusion was drawn that Polish agriculture will need to adapt to the new conditions by undertaking a number of measures, including changing the structure of crops, securing the irrigation of plants against possible droughts with efficient, modern irrigation systems, increasing the genetic diversity of plants, and using modern agrotechnics.