In the mid-eighties, I read a short story about an angel in a heat wave. The author, I think, said the story was originally published in an anthology of religious fantasy (or sci-fi), but I got the impression the author wasn't very religious. The angel arrives in town and it's oppressively hot, foreshadowing the confrontation with a demon that has a family in its clutches in the form of some person or other. Might have been a child involved. I don't remember much else except the story ends with the demon vanquished, the heat dissipated, and rain. Anybody know the story?
I would guess Unworthy of the Angel by Stephen R. Donaldson, which appears in Daughter of Regals & Other Tales. The "demon" is an art gallery owner named Mortice Root who has taken an interest in an artist named Reese and "inspired" him to create dark, powerful sculptures at the expense of his sister Kristen's health. From what I recall, the demon-ness and angel-ness of the antagonist and protagonist are implied more than stated outright.
The story does indeed begin with oppressive heat and end with rain.