The Day of Clear Sky was an attack on House Redwater by the military of the Mohssian Empire. It was a counterattack in response to a string of victories by the Redwater Twins and their allies in the Redwater Uprising. According to Octavia Redwater, the Twins had plenty of advance warning and could have fallen back to live another day but they refused. The attack was nearly as deadly for the Redwater family as the Elroy Massacre had been for House Elroy, and signaled the end of the true Redwater Uprising. However, it came too late to stem the tide of rebellion, as a number of other groups had already been inspired by the successes of the Rainlords and began to defy the Mohssian Empire as well.
In some depictions of the attack, including a painting in the Redwater picture gallery, the clouds are shown to be parted and the sun shining. However, it is unknown if this actually happened, perhaps by some exotic power used by an attacking servant, or if it simply represents the breaking of the Rainlords' power by the Mohssian military.