The village is situated northeast of Terhorne, northwest of Akkrum and west of Grouw. The centre of the village is on the west bank of the river Boorne and has several houses. The river Kromme Grouw connects it with Grouw, to the south is the Prinses-Margriet Canal and to the west is the Sneekermeer.
In the vicinity of Irnsum there is a 108 meter high transmission mast, which can be seen from a large part of the province. The village shares Grou-Jirnsum station with Grouw. In 2019 the village had 1,365 inhabitants. The village also includes the hamlet of Abbengawier and part of the hamlet of Oude Schouw.
Restaurants in Jirnsum
There are no supermarkets in the village of Jirnsum, but if you come by car about 10/15 minutes away you can choose from several supermarkets (Jumbo, Poiesz) and discounters in Grou. Here you can supply yourself with food. In Grou you will find more shops in the city.
In Jirnsum there are two social cafés, both within walking distance of the HA 14 berth.