Precipitation-temperature variability and drought episodes in northwest Baja California, México

•Increased of monthly, seasonal and annual mean temperature (between 0.76–1.82 °C).•Reduction of monthly, seasonal and annual precipitation (between −20 to −172 mm).•Rainfall patterns shifts from positive to negative in 1998.•Drought periods and severity increasing from 1998 to 2016. The semi-arid wine region of Guadalupe Valley located in NW Baja California, México. Recently, recurrent dry years have diminishing groundwater resources threatening agricultural activities and the well-being population in the northwest of Baja California. The climate variability through changes in precipitation and temperature might further the present situation. This study presents the observed long-term (1979–2016) hydro-climatic and temperature trends, extreme events, and drought periods in the Guadalupe Valley for its economic and social relevance in the region. The results revealed the annual/seasonal precipitation rate reduction (from -110 to -172 mm) and an increase in mean annual/seasonal temperature (from 0.76 to 1.82 °C). We detected an abrupt downward change in annual precipitation in 1998, and a continuous period of reduction in precipitation rate from 1999 to 2016 (at least 17 years). Also, we detected an upward change in maximum temperature at 90, 95, 99th percentiles, and an increase in dry seasonal/annual periods after 1998. We linked the length of the meteorological drought to precipitation rate downward and drought severity to years with the lowest annual precipitation. The decrease of precipitation and increase in temperature have had negative impacts on groundwater availability that have affected agriculture and population. Hence specific adaptation strategies are necessary to mitigate regional hydrological impacts.