Abstract: Based on the daily meteorological data of Mêdog national climate observatory, Bomê national basic meteorological station and Zayü national benchmark climate station from 2013 to 2024, as well as the phenological observation data of tea plants in Mêdog, a climate quality evaluation index model for spring tea(I_tcq) was proposed in Mêdog.This model was constructed by combining the meteorological indicator suitability index and the meteorological disaster quality loss index caused by meteorological disasters, and the model was tested in order to provide reference for the evaluation of local tea climate quality and the sustainable development of tea industry. The results showed that the meteorological iicator suitability index (I_acq) for spring tearanged from 1.78 to 2.59, and the meteorological disaster quality loss index caused by agricultural meteorological disasters (Z) ranged from 0 to 0.30 from 2013 to 2024, and the climate quality evaluation index (I_tca) scores ranged from 1.72 to 2.59. The climatic conditions in all years reached the excellent grade of spring tea production,mong which 2013, 2014, 2017 and 2019 reached the super−excellent grade. The number of days with super−excellent grade and excellent grade of spring tea showed a reverse trend during the picking period. The number of days with super−excellent grade was dominant from March 11 to 31, and the number of days with excellent grade was dominant after April 1. Therefore, it was determined that the most suitable picking period for the super−excellent quality of spring tea was before April 1 in Mêdog.

Key words: Xizang, Spring tea, Optimal picking period, Climate quality evaluation index model