Juniperus excelsa M. Bieb, as a native species and valuable natural heritage of Iran, is under threat due to its slow growth and sensitivity to climate change and different plant pathogens. The phenomenon of branch tip dieback (shoot blight) in juniper forests of northern Khorasan has necessitated the investigation of factors affecting the health of these trees. This study investigated the relationship between habitat altitude and dieback severity, and also quantified the influence of climatic and spatial variables on disease index. Sampling was conducted on 40 trees across three elevation groups: low (1596–1634 m, n=20), medium (1778–1805 m, n=8), and high (1869–1895 m, n=12). The health status of each tree was recorded and evaluated based on the following disease rating system (1: healthy to 5: complete dieback). Climate data were extracted from CHELSA V2.1 (2005, 2021) and ERA5-Land reanalysis (2000–2024). Statistical analyses included Kruskal-Wallis, Spearman's rank correlation and stepwise multiple linear regression. The medium elevation group exhibited the highest disease severity (mean=3.75, median=4.0). Kruskal-Wallis analysis revealed significant differences across elevation groups (χ²=7.991, p=0.018). Spearman's correlation showed significant relationships between disease and spatial variables (Northing: ρ=-0.427, p<0.001; Easting: ρ=-0.119, p=0.009). Multiple regression identified elevation and easting as the only significant predictors (R²=0.412, Adjusted R²=0.410, p<0.001), while month and temperature were not significant when spatial variables were included. Summer precipitation correlated negatively with disease (ρ=-0.452, p=0.003), indicating drought stress amplifies dieback. The 1778–1805 m elevation range was identified as a critical zone for disease outbreaks, while altitudes above 1869 m represented a relatively safe zone. Elevation, not temperature alone, emerged as the primary driver of dieback, with temperature effects acting as proxies for the underlying elevation gradient. These findings provide a quantitative framework for targeted conservation and monitoring of juniper forests. Continuous monitoring of the identified critical area and investigation of related microbial factors in subsequent phases of research can lead to a more comprehensive understanding of the causes of dryness and the development of practical solutions for the preservation and restoration of this nationally valuable ecosystem.