Rainbow Splash was born in Cloudsdale, during the time Griffons began fleeing their kingdom due to the Changeling Invasion and assassination of their King. Rainbow grew up in an orphanage, due to both her father being MIA in the Fireflies (Alternate name for the Wonderbolts. Yes I just watched Testing Testing 1, 2, 3.) and her mother dying in a weather factory accident in the snowflake section, when a flurry blew in and knocked the bigger snow flakes down. Splash met Glenda in the orphanage, a griffon who had also lost her parents, but in the invasion of the Griffon Kingdom. The two became fast friends, and flying partners.
 
As Splash grew older, she began to be more active and proud. She was a smart-mouth and brash, and wished to prove herself. One day as a filly, she challenged two older colts in a race. This race lasted fifteen minutes, in which a harsh gust of wind knocked all the pegasi off course and to the ground. Rainbow Splash survived the fall miraculously, while the two colts she challenged were severely injured. Due to this, Rainbow immediately grew shy and terrified to speak up, and her ego shrunk rapidly.
 
Splash found her talent in the weather, mostly storms. She could handle most storms that go along with clouds, but tornadoes are out of her hooves, and she will have a minor panic attack at the mere feel of a strong breeze. Splash managed to find work, but her excessive fright of being close to another pony (other than Glenda) made her very uncomfortable. She prefers to be alone, or if not, with Glenda.
 
Glenda went onto join the Fireflies Reserves, and still regularly hangs out with Rainbow when she can.