P. SRINIVASA SASDHAR *

Department of Economics, Vijayanagara Sri Krishnadevaraya University, Ballari – 583105, Karnataka.

ABSTRACT

Diurnal temperature range (DTR), the difference between daily maximum and minimum temperature, is an important indicator of asymmetric warming. This study analyses long-term spatial variability in DTR across Karnataka, India, using district-level temperature series derived from the TerraClimate dataset for 1958–2024. Annual DTR trends were evaluated using the non-parametric Mann–Kendall test and Sen’s slope estimator. Results indicate pronounced spatial heterogeneity across districts. Increasing DTR trends occur primarily in southern Karnataka, whereas decreasing trends dominate northern semi-arid regions. Several coastal districts exhibit weak or non-significant trends. These findings demonstrate that aggregated temperature indicators mask substantial regional variability in diurnal thermal behaviour.

KEYWORDS: Climate variability; diurnal temperature range; Karnataka; mann–kendall test; spatial analysis.