NASA and SpaceX had closely watched weather conditions throughout the day, as local thunderstorms passed through the Kennedy Space Center in Florida.
Additionally, severe weather off the coast of South Carolina was a factor that launch directors were monitoring, as conditions on the surface of the Atlantic Ocean could affect the spacecraft in the event of an abort mid-launch.
Before the weather delay, the SpaceX countdown was smooth and without technical hurdles or hitches for an estimated launch time of 4:33 p.m.
The company will try again to launch the Demo-2 mission on Saturday at 3:22 p.m.
"Due to the weather conditions, the launch is scrubbing," NASA wrote.