Umag is situated 2 boarder crossings and about 50 km south of Trieste, year around there are daily direct buses between the cities, travel time of the bus is about 1 hour and 30 minutes. The bus departures from main bus station in Trieste, which is in the centre of town next to the train station. In Umag the bus stops at the main bus station, which is within walking distance of the old town, but a bit away from the main hotel area. You can see timetable for buses between Trieste and Umag below and here you can see schedule for bus in the opposite direction.