We concluded an investigation of the occurrence of the Mediterranean fruit fly (Ceratitis capitata, Diptera, Tephritidae) at four locations in 2016 (Brje na Vipavskem, Tublje pri Komnu, Solkan, Cikuti), and at 2 locations in 2017 (Brje na Vipavskem, Cikuti) in the Primorska region between August and November. The population was monitored using 3 different traps, 2 of which were pheromone traps (Jackson trap, type delta, and Storgard trap) and 1 a food-based trap (attractant trap Tephri containing insecticide). We changed the pheromone capsule once a month, and performed regular checks of the traps every 10 days. The medfly was caught in both years. The first appearance of the fly was on the 10th of September. In 2016, we captured 32 flies at 4 locations, followed by 56 flies at 2 locations in 2017. In 2016, the fly appeared earlier than it did in 2017. It was caught more frequently in Tephri traps. The occurrence and abundance of the medfly were a consequence of temperature, precipitation and humidity. Certain conditions needed to be present for Mediterranean fruit fly to appear. The average daily temperature had to be below 15 °C, humidity had to reach over 80 %. Precipitation was an important factor. The majority of flies started to appear during long periods of dry weather, followed by rain.