Continuous water-temperature data were collected at multiple sites along the Middle Fork and mainstem Willamette Rivers between Jasper and Newberg, Oregon, to support effectiveness monitoring for a large-scale channel and floodplain restoration program (Willamette Focused Investment Partnership, WFIP). Continuous water temperature loggers were deployed at a subset of WFIP restoration sites where river restoration activities were implemented to improve habitat conditions for native fish species. Data from water-temperature monitoring will be used to evaluate the effectiveness of restoration activities at improving habitat conditions for ESA-listed salmonids and other native fish in the Willamette River. Additionally, water temperature monitoring in summer and early fall months at restoration sites is useful for determining whether thermal conditions at these sites are optimal, sub-optimal, or lethal for cold-water adapted fish species like spring Chinook salmon (Oncorhynchus tshawytscha). Temperature monitoring for this study spans 2019 through 2022. Water-temperature loggers were suspended in the water column on a wire between a concrete block and a buoy as part of a monitoring arrays installed at multiple off-channel location throughout the study area. This document describes data collected at the Collins Bay monitoring site between 06/27/2019 and 10/21/2020. The monitoring site is within an alcove perennially connected to the Willamette River and includes one monitoring array consisting of two water-temperature loggers suspended in the water column from 06/27/2019 to 07/30/2020 and then one-logger from 07/30/2020 to 10/21/2020.