Understanding Spatio-Temporal Dynamics of Extreme Rainfall and Temperature Events over state of Bihar, India

The present study examines changes in extreme temperature and rainfall patterns across Bihar’s districts over a span of four decades (1982–2022), focusing on their spatial and temporal dynamics. Daily weather data for parameters such as maximum temperature, minimum temperature, and rainfall were sourced from the NASA-POWER database (https://power.larc.nasa.gov) to compute climate extreme indices. The formulation of these indices adhered to the standardized approaches suggested by the ETCCDI and ET-SCI for consistent climate change and sector-specific climate analysis. Notably, this is the foremost comprehensive analysis focusing on the temporal trends of climate extremes at the district level in Bihar. Bihar's climate trends spanning four decades exhibit notable transformations in meteorological variables. Reduced summer days hint at a cooling trend, while lengthen tropical nights reflect nocturnal warming. Although warm days decrease uniformly, warm nights surge in most districts. Diverse patterns emerge in monthly maximum temperatures (TXx), with some south-western districts bucking the trend. Rising minimum temperatures are evident except in Katihar and Jamui. Crucially, heavy rainfall dynamics are pivotal, with escalating events varying by time frame and locale. Eastern districts face increased short and medium-term heavy precipitation risks, while the central and western regions encounter prolonged heavy rainfall episodes over five days (Rx5day). Changing dry and wet day frequencies impact water resources and agriculture, accentuating the need for tailored adaptation strategies. Bihar's climatic complexity underscores regional disparities, emphasizing the urgency of responsive environmental awareness and strategies.