Precipitation Dependence of Temperature Trends Across the Contiguous US

Temperature and precipitation covary across timescales due to thermodynamic and dynamic processes. We examine spatial patterns and trends of daily precipitation dependence of maximum and minimum temperature anomalies across the contiguous United States during 1950-2020. In the warm season, maximum temperatures are anomalously cool on wet days, while in the cool season, minimum temperatures are anomalously warm on wet days. During 1950-2020, warm-season maximum temperatures increased 0.5 degrees C more on wet days than on dry days, whereas minimum temperature on dry days warmed slightly more than on wet days in both the warm and cool season. By contrast, climate models show more subtle and consistent precipitation dependence of temperature trends with approximately 0.2 degrees C more warming on dry days than on wet days. Improved understanding of precipitation-dependent temperature trends is critical for understanding and modeling the impacts of changing climate on snowpack, drought, and heat stress.

Automated summary

Temperature and precipitation are found to be covariant across timescales. In the contiguous United States, maximum temperatures are anomalously cool on wet days in the warm season, while minimum temperatures are anomalously warm on wet days in the cool season. Climate models exhibit a subtle precipitation dependence of temperature trends.