In situ mean annual temperature (MAT) data was calculated from temperatures logged at hourly intervals from 9 lakes and 17 soils in Chile, between -38.2º and -44º latitude, including the Auracania, Chiloé Island, and Chiloé Mainland regions. In situ temperature data loggers (HOBO TidbiT v2 Temperature Data Logger; ±0.2 °C accuracy) were installed at ca. 1 m from the lake surface and at 5 cm depth in soils for varying years (from one to five total years, the earliest logs began in 2017 and the latest were removed in 2022). We additionally obtained modeled Mean Annual Air Temperature (MAAT) values from three different sources for comparative analysis. We extracted data for our sample locations using the ncdf4 (v. 1.21; Pierce, 2023, https://CRAN.R-project.org/package=ncdf4) and raster (v. 3.6-23; Hijmans, 2023, https://CRAN.R-project.org/package=raster) R (v. 4.3.1; R Core Team, 2023, https://www.R-project.org/) packages.CR2MET (v. 2.0): Files were downloaded from El Centro de Ciencia del Clima y la Resiliencia (CR)2 (https://www.cr2.cl/datos-productos-grillados; file name CR2MET_v2.0_t2m_mon_1979_2019). The dataset consists of mean monthly air temperatures at 2 meters from the surface that were derived from a reanalysis product of satellite and in situ observations with a resulting spatial resolution of 0.05° (ca. 5.6 km at the equator). The reanalysis products were calibrated against regional meteorological station observations by (CR)2 and cover the period from 1979 to 2019 for the country of Chile alone.WorldClim (v. 2.1): Files were downloaded from the WorldClim database (https://worldclim.org/data/worldclim21.html). This dataset is derived from spatially interpolated gridded monthly data from meteorological station and satellite observations with a spatial resolution of 30 arc-seconds (ca. 1 km at the equator) and cover the period from 1970 to 2000 (Fick and Hijmans, 2017; doi:10.1002/joc.5086).CHELSA (v. 2.1): Files were downloaded from the CHELSA (Climatologies at high resolution for the earth's land surface areas) database (https://chelsa-climate.org/bioclim/). This dataset is derived from the ERA-Interim climatic reanalysis using post-processing Model Output Statistics with correction from meteorological station observations, resulting in a spatial resolution of 30 arc-seconds (ca. 1 km at the equator) and covering the years 1979 to 2013 (Karger et al., 2017; doi:10.1038/sdata.2017.122).In situ and modeled temperature data were collected in order to compare to the distribution of branched glycerol dialkyl glycerol tetrather lipids (brGDGTs), emerging proxies for temperature.