The issues related to bioclimatic comfort and their impact on human health are significant factors that underscore the importance of assessing and monitoring the thermal environment in human biometeorology. The human perception of the surrounding environment cannot be captured by examining only one meteorological parameter such as temperature, relative humidity or wind speed. Instead, it is the interplay of these factors that influences human comfort.
The humid climate of the Gilan province means that even relatively low temperatures, which may create comfortable thermal conditions in drier areas, can lead to cautionary situations in this region. This study presents a case analysis of the heat index (HI) and effective temperature index (ET) in Gilan province, utilizing output from the GFS model with a horizontal grid resolution of 0.25 degrees and a three-hour time step for index calculations.
Analysis of the synoptic maps indicates a stable atmospheric column over Gilan province. The results show that for the specified day, the HI index indicated a second degree warning for certain areas within the province, while the ET index was assessed as a third degree warning for some regions. These findings are consistent with the observed temperature and humidity levels, and the thermal index maps effectively highlight the associated alerts.
Notably, the relative humidity in Gilan province is higher than in many other regions of the country. Consequently , despite the lower temperatures, the perceived temperatures in this region is significantly elevated, resulting in thermal index warning comparable to those in many hotter regions of the country.