Change in the Diurnal Temperature Range over Puerto Rico between 1950-2014

This paper analyzes the spatial dependence of annual trends in the diurnal temperature range (DTR) of Puerto Rico (PR) from 1950–2014. The DTR is a useful indicator of climate change and average temperature changes. Observation records indicate that the DTR has decreased in the last 64 years because of changes in the difference between the minimum and maximum temperatures. The 13 studied meteorological stations have shown a negative trend of −1.33 in the DTR for PR. The minimum temperature (Tmin) has shown a greater increase than the maximum temperature (Tmax) over the period analyzed. Because of this behavior, the stations can be categorized into two large groups. For nine stations (Aguada, Ceiba, Guayama, Isabela, Manatí, Mayaguez, Lajas, Ponce, and San Juan), the variability of the minimum temperature in the mountain of Puerto Rico increased during the 1970s, while for four stations (Aibonito, Corozal, Juncos, and Utuado), Such an increase in average temperature was manifested later, in the 1980s. The Mann-Kendall analysis shows that nine out of the thirteen stations have a p-value 0.005, this shows that the tendency to decrease of the DTR is strong. A more detailed analysis is recommended to determine the cause of this behavior.