Fragmentation and loss of natural habitats has reduced biodiversity in neotropical ecosystems. The restinga, a phytophysiognomy of the Atlantic Forest, has lost much of its original coverage and remains largely threatened by urbanisation. Restingas are considered hotspots of biodiversity and are listed as priority areas for conservation due to their great presence of endemic species, such as the endangered butterfly Parides ascanius Cramer, 1775. In this work, we analyse the influence of abiotic factors (temperature and humidity) on the abundance of P. ascanius in an urban restinga fragment of Iriry’s Environmental Protection Area (Iriry APA), located in the municipality of Rio das Ostras in Rio de Janeiro. For that, the mark-recapture technique was used. Sampling was carried out from October 2017 to May 2018, between 7:00 am and 11:00 am. Seventy-two individuals of P. ascanius were collected and showed higher proportions of males over females and greater abundance of individuals in the month of October. On average, the number of individuals was significantly higher with the increase in air temperature and lower with the increase in air humidity. The abundance of P. ascanius at the restinga of Iriry APA varied monthly and temporally throughout the day, influenced by temperature and air humidity. The results provide information that can support management plans for conservation of this threatened species, as well as for urban areas of the Atlantic Forest.