The UNSC Fair Weather was a United Nations Space Command frigate. In 2552, the Fair Weather was part of Admiral Micheal Stanforth's fleet which arrived in orbit around Sigma Octanus IV. When Covenant forces returned to the system, the Fair Weather took part in the ensuing confrontation, the Battle of Sigma Octanus IV. It collided with a Covenant destroyer and as the structures of the two vessels interlocked, they fired all weapons at each other at point-blank range. The Fair Weather was destroyed by the Covenant's superior plasma weaponry, but it managed to take the Covenant ship down with it.