Smart objects are increasingly widespread and their ecosystem, also known as the Internet of Things (IoT), is relevant in many application scenarios. The huge amount of temporally annotated data produced by these smart devices demands efficient techniques for the transfer and storage of time series data. Compression techniques play an important role toward this goal and, even though standard compression methods could be used with some benefit, there exist several ones that specifically address the case of time series by exploiting their peculiarities to achieve more effective compression and more accurate decompression in the case of lossy compression techniques. This article provides a state-of-the-art survey of the principal time series compression techniques, proposing a taxonomy to classify them considering their overall approach and their characteristics. Furthermore, we analyze the performances of the selected algorithms by discussing and comparing the experimental results that were provided in the original articles. The goal of this article is to provide a comprehensive and homogeneous reconstruction of the state-of-the-art, which is currently fragmented across many articles that use different notations and where the proposed methods are not organized according to a classification.