Welcome to Kiruna!
Here are links for flights and trains to and from Kiruna. The most comfortable and fastest way to reach Kiruna is to fly. Lower down on the page there are also links to other public transport/transfers in Kiruna.
Notice: At the end of August the weather can be variable, by up to +10 C. Be sure to bring warm clothes. Outside town and around the IRF building there can be a lot of mosquitos so you may want to buy insect repellant.