<p>India is one of the largest landmasses under agricultural production. Irrigation is widely recognized as a key adaptation strategy for stabilizing crop yields under rising temperatures and rainfall variability. Yet, the extent to which irrigation mitigates climate-induced yield fluctuations remains spatially heterogeneous and insufficiently quantified at fine administrative scales. Using 50 years (1966–2015) of district-level data from 175 major wheat-producing districts across India, this study examines the relationships between wheat yield variability, irrigation coverage, and temperatures. We examine the wheat yield variability by aggregating the annual deviation from long-term yield trends and quantify the long-term irrigation fractions across Indian districts. We combine time-series regression models to assess interannual yield–irrigation linkages with panel fixed-effects models to evaluate how varying irrigation modify the temperature–yield relationship. The analysis reveals: (1) wheat yield variability is substantially lower in districts with higher irrigation coverage; (2) irrigation expansion has positively affected yields in 142 districts, accounting for ~ 76% of India’s wheat-harvested area; and (3) irrigation offsets, but does not fully eliminate, the negative effects of temperature increase on yield. The results demonstrate that irrigation’s beneficial effects are strongest in north-western India, where coverage exceeds 90%, but weaken in less irrigated and groundwater-stressed regions. By integrating spatially explicit and long-term analyses, this study provides empirical evidence for the limits and regional disparities of irrigation-based adaptation, offering insights relevant to climate-resilient agricultural planning in South Asia and comparable semi-arid regions globally. The manuscript is relevant to an international audience, as India accounts for ~ 14% of global wheat production and is the second-largest wheat producer globally.</p>