Extreme weather events have become more frequent and severe in recent years, with projections indicating their increased occurrence in the future. While extensive research has focused on assessing the impact of gradual climate changes, there has been less attention on how populations respond to single and sporadic extreme weather events. This study examines the population dynamics of Phengaris arion and its host plant Thymus serpyllum to an extreme drought event that occurred on the island of Gotland in Sweden in 2018. The investigation spans the years 2018-2022, focusing on the immediate impacts of the drought and tracking the subsequent recovery of the populations. Using generalised linear mixed effects models, the probability of presence, colonisation and extinction of P. arion and T. serpyllum were evaluated across years and in relation to ground moisture (measured as ground moisture index, GMI), shrub cover and tree cover. The results show that there was a population collapse of P. arion in the year following the drought and a subsequent quick recovery in only three years. The butterfly utilised areas with more tree cover in the year of the drought (2018) and was present in areas with relatively high shrub cover irrespective of year. Colonisation probability was highest in areas with little or no tree cover and the association with ground moisture varied across years. Extinction probability was independent of ground moisture, shrub cover and tree cover and occurred independent of analysed grid characteristics. The average frequency of T. serpyllum was stable in 2019-2021 and increased significantly in areas with little tree cover in 2022. The different habitats used during and after the drought, coupled with the continuous presence of the host plant, may have mediated the fast recovery of P. arion. These findings underscore the need for a comprehensive approach to conservation, considering not only a species' typical habitat but also the habitat it utilizes during extreme weather events.