The first summer temperature reconstruction for the Caucasus region based on maximum latewood density

The Caucasus region has received little attention in paleoclimate research despite its complex climate dynamics that are linked with Mediterranean and European climate as well as with Asian monsoon systems. In this study, we present the first summer (June-September) temperature reconstruction based on maximum latewood density in tree rings from the Caucasus. With highresolution X-ray micro–Computed Tomography scanning from Pinus sylvestris increment cores, we developed a record spanning the past four centuries (1629-2022). By integrating multiple detrending techniques and reconstruction methods, we assess the impact of methodological choices on reconstruction outcomes and performances. The resulting ensemble-mean reconstruction explains over 60% of the temperature variability during the period of instrumental observations (1901-2022). Reconstructed temperatures reveal distinct multi-decadal variability, a clear signal of recent warming and a response to short-lived volcanic forcing. Our record reflects a weak but discernible signal of temperature variability associated with the Little Ice Age. Spatial correlations between our reconstruction and gridded summer temperatures are highly significant across a broad region spanning the Black and Caspian Seas. Comparison with a blue intensityderived temperature reconstruction from the Greater Caucasus shows strongest agreement in the high-frequency domain. Differences at multidecadal to centennial timescales may be due to local site-related factors or proxy limitations. Our results emphasize the importance of filling a significant gap in Northern hemisphere temperature history and hint to the potential of extending temperature-sensitive tree-ring chronologies by dating historical wood samples from the Caucasus region to enhance the spatiotemporal coverage of climate reconstructions.