Maintaining sustainable heating price levels is a crucial aspect of the future development of district heating (DH) systems to provide a low-carbon and affordable heat supply. The recent extreme increase in resource prices during the energy crisis in 2022/2023 has raised an important question of how to increase the overall resilience of energy systems. This research focuses particularly on the ability of DH systems to maintain affordable heat price levels under significantly increased resource prices. The simple definition of resilience has been attributed to the ability of a system to recover from adversity. A novel resilience capacity quantification methodology has been applied. The research analyses 10 different DH systems in Latvia with various heat production technologies and fuel mixes and their changes in heat prices from 2021 to 2023. The study identifies the resilience curves of each DH system and compares their ability to recover after the disruption. A composite resilience index has been developed for the DH supply systems of several municipalities in Latvia. To construct the DH resilience composite index, indicators were selected and grouped into four dimensions: technical, economic, environmental, and social. The DH resilience composite index merges fourteen criteria and compares which DH systems are more resilient to extreme changes in external conditions.