The purpose of the article is to review the concepts for creating web applications, analyze the advantages and disadvantages of modern technologies for weather forecasting. The article presents modern client-server technologies. The concept of a single-page application and other technologies that allow interaction between the client and the server online are discussed in detail. The development of an application for tracking weather conditions based on the architecture of the SPA is presented. The research methodology includes processing theoretical information and analyzing the architecture of the application, built on the principle of SPA, analyzing the advantages and disadvantages of approaches to client-server interaction, using Angular, Vue, React libraries, using APIs to create applications. The novelty of the research is the analysis of the modern concepts and technologies that allow you to develop web applications that can be used to build a modern web application of the Single Page Application concept, a detailed analysis of Angular, Vue, React libraries and user interaction with such systems, analysis of Service Workers technology as a way of hashing. Conclusions. The article analyzes modern technologies for creating web applications, presents their advantages and disadvantages, discusses the concept of Single Page Application and describes the development of an application for tracking weather conditions, provides analogues for comparative characteristics, discusses problems that arise when the client part interacts with the server application of SPA principles.