The Oxford Dictionary of Surnames says:
HALE, HALES:
William de Hales 1180 (Shropshire);
Robert Attehal' 1212 (Lincolnshire);
John del
Hale 1220 (Hertshire);
Nicholas en la
Hale 1275 (Worcestershire);
John in the
Hale 1296 (Sussex).
From residence in a nook, recess or remote valley. Old English "halh" (nom.) becomes Haugh, Hauff, Hallowes. The dative (atte) hale becomes
Hale. (also Haile, Heal)
Andy ;—)