Climate change affects tree growth in the Himalayan region, where tree rings record how trees respond to environmental and climatic conditions. Combining wood anatomical traits with tree-ring width data can provide a better understanding of climate-growth relationships, yet the integrated application of these approaches remains limited for Himalayan forests in Bhutan. We analyzed tree-ring width (TRW) and time series of earlywood (EW) and latewood (LW) anatomical characteristics of Himalayan blue pine (Pinus wallichiana) in central Bhutan to identify key climatic controls and drivers of radial growth. Climate sensitivity analysis showed that differential climatic control of seasonal growth, particularly earlywood growth, was primarily limited by spring moisture availability, whereas latewood growth responded positively to minimum temperatures throughout the growing season. Sufficient moisture availability promoted larger lumen area (LA) in EW and TRW but was negatively associated with higher maximum temperatures during the transition period between the pre-monsoon and rainy summer seasons, indicating that heat stress restricts tracheid enlargement. Earlywood cell wall thickness decreased with moisture surplus, while latewood cell wall thickness declined with high August temperatures, suggesting that heat stress restricts wall deposition. Our results demonstrate that wood anatomical traits reveal climate signals not captured by ring width alone. Integrating tree-ring width and wood anatomy improves understanding of climate sensitivity and conifer growth in Bhutan.