Those taking part enjoyed a dry walk to 'the Field' on Moneymore Road after arriving on buses at Castledawson Road.
But the thunder clouds eventually opened and the rain came down before drying up for the return procession through the town.
Eight Districts were on parade - Ballyronan, Castledawson, Garvagh, Kilrea, Moneymore, Tamlaght O’Crilly, Tobermore and the host District Magherafelt.
About 50 bands and lodges took part and spectators enjoyed a great spectacle of music and sights.
17. On parade
A young flag carrier on the march in Magherafelt. Credit: National World Photo: National World
18. On parade
Brethren making their way to 'the Field' on the Moneymore Road, Magherafelt. Credit: National World Photo: National World
19. On parade
Tobermore District taking part in the Twelfth demonstration in Magherafelt. Credit: National World Photo: National World
20. On parade
LOL 228 stepping it out at the Twelfth demonstration in Magherafelt. Credit: National World Photo: National World