Thundering Nights is the first foal of her dam Cape Castle who showed modest ability on the track, winning four minor races in England as a four-year-old in 2015.
[5] She was a granddaughter of Cloud Castle who won the Nell Gwyn Stakes and was closely related to Kris Kin, Warrsan and the multiple Group 1 winner Luso.
After finishing fourth in a similar event at Gowran Park on 14 October she started a 14/1 outsider for a maiden over eight and a half furlongs at Galway Racecourse two weeks later.
Ridden by the apprentice jockey Shane Crosse she raced in seventh place before making steady progress in the straight and gained the advantage inside the final furlong to win by half a length from the odds-on favourite Mazara.
[8] The filly was then stepped up in class for the Group 3 Snow Fairy Stakes over nine furlongs on soft ground at the Curragh and started the 7/2 second choice in the betting behind Albigna in an eight-runner field.
"[10] On 13 September Thundering Nights started at 9/1 for the Group 2 Blandford Stakes over ten furlongs at the Curragh and finished third behind Cayenne Pepper and Amma Grace.
For her final run of the year she was sent to England for the Group 1 British Champions Fillies & Mares Stakes over one and a half miles at Ascot Racecourse in October and came home seventh of the twelve runners behind Wonderful Tonight, beaten eleven lengths by the winner.
Racing in heavy rain, Thundering Nights turned into the straight in fourth place before finishing strongly but failed by a nose to catch the front-running Mean Mary.