The authors propose a new climatic drought index called the Standardized Precipitation Evapotranspiration Index (SPEI). This index combines precipitation and temperature data, offering a multiscalar approach that accounts for the effects of temperature variability on drought assessment. The SPEI is calculated using a climatic water balance, accumulating deficits/surplus at different time scales and adjusting to a log-logistic probability distribution. Mathematically, it is similar to the Standardized Precipitation Index (SPI) but includes temperature. The SPEI is compared with the self-calibrated Palmer Drought Severity Index (sc-PDSI) and the SPI for various observatories with different climate characteristics. Under global warming conditions, only the sc-PDSI and SPEI identified an increase in drought severity due to higher water demand from evapotranspiration. The SPEI's advantage over the sc-PDSI lies in its multiscalar nature, which is crucial for drought analysis and monitoring. The SPEI is shown to be effective in detecting, monitoring, and exploring the consequences of global warming on drought conditions, making it a valuable tool for climate change research and water resource management.The authors propose a new climatic drought index called the Standardized Precipitation Evapotranspiration Index (SPEI). This index combines precipitation and temperature data, offering a multiscalar approach that accounts for the effects of temperature variability on drought assessment. The SPEI is calculated using a climatic water balance, accumulating deficits/surplus at different time scales and adjusting to a log-logistic probability distribution. Mathematically, it is similar to the Standardized Precipitation Index (SPI) but includes temperature. The SPEI is compared with the self-calibrated Palmer Drought Severity Index (sc-PDSI) and the SPI for various observatories with different climate characteristics. Under global warming conditions, only the sc-PDSI and SPEI identified an increase in drought severity due to higher water demand from evapotranspiration. The SPEI's advantage over the sc-PDSI lies in its multiscalar nature, which is crucial for drought analysis and monitoring. The SPEI is shown to be effective in detecting, monitoring, and exploring the consequences of global warming on drought conditions, making it a valuable tool for climate change research and water resource management.