Unraveling Urban Heat and Moisture Anomalies Across the Continental U.S. Using Local Climate Zones and Earth Observation Data

Urban environments fundamentally alter local climate conditions, creating distinct thermal and hydrological patterns that impact public health, energy demand, and urban sustainability. While urban heat islands are well-documented, the spatial variability of urban moisture anomalies—encompassing both Urban Dryness Islands (UDI) and Urban Moisture Islands (UMI), across different urban morphologies remains poorly quantified. This study leverages high-resolution Local Climate Zone (LCZ) classifications (100 m) integrated with satellite-derived Land Surface Temperature (LST), evapotranspiration, precipitation, and NDVI data for 2020 across the conterminous United States. We quantify urban heat island intensity as LST differences, comparing the LST of each individual built environment LCZ type (LCZ 1–10) against the average LST of its corresponding local natural area reference zone. This local natural area reference zone is defined as the spatially contiguous non-urban LCZ types (LCZ A–G) within a 1 km buffer. Urban moisture anomalies are assessed through evapotranspiration and precipitation contrasts relative to the buffered reference zones . A Random Forest model will predict LST using LCZ type, NDVI, evapotranspiration, and precipitation as predictors, enabling identification of key drivers governing urban climate variability. Feature importance analysis reveals the relative contributions of urban form versus environmental factors in determining thermal and hydrological responses. Preliminary results demonstrate pronounced LCZ-dependent climate modifications. Compact mid-rise developments exhibit consistent warming (UHI = 0.57°C, p = 0.014) with strong drying effects (UDI = 399.9 mm/year, p < 0.001), while compact high-rise zones show cooling patterns (UHI = -2.55°C, p = 0.010) despite intense moisture depletion. Open low-rise residential areas demonstrate moderate warming (UHI = 1.37°C, p < 0.001) with significant moisture increases (UMI = 325.4 mm/year, p < 0.001), and vegetated zones display strong cooling effects (UHI = -7.32°C for dense trees). These findings establish a quantitative framework linking urban form to climate impacts across diverse regional contexts, providing critical insights for climate-adaptive urban planning and design strategies that can mitigate adverse thermal effects while managing urban water cycles more effectively.