Mackerel sky,
Rain is nigh.
or
Mackerel sky,
Rain to-morrow.
Brookline, Mass.

Mackerel sky,
Rain is nigh.
or
Mackerel sky,
Rain to-morrow.
Source: Current Superstitions (1896), entry 1023.
Fanny D. Bergen, editor.
Modern normalized navigation; the historical attribution above remains unchanged.