Dataset: Winter temperature data from loggers placed in shallow subtidal areas in the northeast Pacific from Oct 2019 to Jul 2024

Loggers were placed in the shallow subtidal in areas determined by Washington Sea Grant's Crab Team to be good environment for green crabs. Loggers were placed by multiple collaborators without a fully standardized approach; metadata are incomplete but include all available information. Loggers used were iButtons (Maxim Integrated; models DS1921G, DS1921Z, or DS1921G-F5) in 2019-2023, switching to HOBO loggers (Onset; model MX 2201) in 2022 (Makah Bay) or 2023 (all sites). iButtons were housed in waterproof housing capsules (DS9107), and both types of logger were placed within short lengths of PVC, which were open at both ends, to allow water flow but reduce temperature changes related direct light exposure, and any physical damage. Two loggers were placed at each site in the shallow subtidal, generally anchored on cinderblocks or pieces of PVC pushed into the substrate. Loggers were typically started before they were deployed in the field, sometimes weeks before, so include some air temperature data before deployment; metadata includes actual dates and times of deployment  when known. Logging frequency varied by model: iButtons were set to log every 2.15 hours, and HOBOs logged every 30 min over the winter. Duration varied between years and sites, but typically ran from October - April. Loggers were generally not set to roll over (but see notes), and data were retrieved in the spring.