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Land surface temperature (LST) is an important parameter to characterize the surface-air exchange process, which has played an important role in climate change, ecological monitoring, hydrological simulation, and other studies. Although the traditional LST estimated from thermal infrared (TIR) remote sensing has been mature in terms of retrieval methods, data production, and quality control, the TIR LST has a lot of missing data under clouds due to the limitation that TIR radiation from the ground surface is not able to penetrate the clouds. In addition, passive microwave (PMW) remote sensing also has disadvantages such as strip gaps and coarse spatial resolution due to limitations of the physical mechanisms and imaging methods. Therefore, it is very important to obtain the all-weather LST unaffected by cloudiness to support related subsequent studies. In this paper, we review and organizes the basic principles and methods of the acquisition of all-weather LST. The methods are classified into two categories: (i) all-weather LST reconstruction from effective observation; and (ii) integration of multi-source data. Through comparative analysis, we found that multi-source data integration can combine the advantages of TIR, PMW, and reanalysis data, and thus, it has the most research value and potential for further research. Multi-source data integration can be employed to obtain global long-time all-weather LST products characterized by spatial and temporal continuity. Though the LST retrieved from passive microwave remote sensing suffers from coarse spatial resolution and strip gaps, it is still an effective method of obtaining land surface information under clouds and an important input parameter for multi-source data integration. The reconstructions of all-weather LST based on effective observation are only applicable to small areas with cloud cover in short periods and are not practicable for long-term cloudy areas. In the process of analysis and conclusion, this paper also collects and analyzes information about five currently released all-weather surface temperature products, and summarizes the advantages and disadvantages of the existing products. We note that a global all-weather LST product with high quality and spatial resolution is urgently needed by the scientific community. After reviewing the all-weather LST products, we further summarized the applications of all-weather LST. We found that its application is still in infancy. Research on the application of all-weather LST is relatively small in the current stage but has great potential for application when its products further mature. Finally, further study directions and theoretical development of all-weather LST are discussed and prospected. Firstly, there are two issues that need to be addressed with PMW LST as the basis for all-weather LST: (i) filling PMW LST strip gap, so that passive microwave surface temperature has more complete spatial coverage; (ii) correcting thermal sampling depth to make that PMW LST has the same physical meaning as TIR LST. Because the inconsistent observation caused by the inconsistent thermal sampling depth is the essential reason for the inconsistent physical meaning of PMW and TIR observation information. Secondly, we should further strengthen the study on the estimation of all-weather LST from multi-source data. The current study of multi-source data integration is still in the preliminary stage and no systematic and effective integration strategy has been developed. Thirdly, the scientific community should enhance the production, publication, and application of all-weather LST products. Few all-weather LST products can be directly applied by users. The generation of all-weather LST products with global spatial and temporal continuity, as well as high spatial resolution should be the task of all-weather LST study. Besides improving the data quality and reliability of all-weather LST, we should focus on the operability and cost of the method in practical applications, so that the all-weather LST can become usable data, thus truly promoting the progress of the related studies.