The fluctuations in climatic factors, such as precipitation and temperature, play a significant role in driving changes in the normalized difference vegetation index (NDVI). Our study aimed to assess and analyze the inter-annual variation in the NDVI of wild trees in the Zhongar Alatau mountain region, specifically within the Zhongar Alatau State National Natural Park (SNNP), spanning from 2006 to 2023. We focused on data collected in August to understand the seasonal dynamics of NDVI in this area. NDVI values and their classifications were derived from Landsat imagery (Landsat 4-5, 8-9), which were processed using QGIS software. We created maps depicting NDVI values for the Zhongar Alatau SNNP, as well as diagrams illustrating the inter-annual variation of NDVI, precipitation, and temperature. On average, NDVI values of wild trees in the study area ranged from 0.31 to 0.44, with maximum values reaching approximately 0.50–0.55. The findings of the study relationship between climatic factors and NDVI values that NDVI demonstrates a positive correlation with precipitation while showing minimal correlation with temperature by using simple linear regression, and correlation coefficient analysis. In specific years such as 2006, 2008, 2014, 2016, and 2021, notably low NDVI values were identified, as closely associated with precipitation levels. The short intervals between these unfavorable years may contribute to genetic erosion within wild tree populations. These results highlight the critical importance of conserving biodiversity among wild trees, particularly by considering the trends in vegetation responses to climate change.