The paper presents a prediction of changes in the potential areas of tertian malaria till 2025. It shows that possible climatic changes whose main features are an increase in average annual temperatures do not imply a uniform expansion of areas for parasitic infections. The regional and seasonal trends of temperature changes in Russia (both established for the 20th century and predicted for the early 21st century) will both expand the area in its one part and reduce in its another part. Overall, the changes caused by climatic factors in the potential area of human malaria in Russia in the first quarter of the 21st century will not lead to a drastically aggravated malaria epidemiological situation.