How does Friar Laurence describe the hour? What does he mean?

Friar sees the blood and mayhem from the fight between Romeo and Paris. He calls the hour "unkind" that displays the blood, dead Paris, and the general violence that has taken place so close to a sacred shrine (Capulet shrine).

Romeo! O, pale!—Who else? What, Paris too?
And steeped in blood?—Ah, what an unkind hour
Is guilty of this lamentable chance!
The lady stirs.