The breeding male is olive-green above. A black line runs through the eye. The underside is gray-white without streaks. Wing bars are absent. The black line through the eye is present and the throat and the rest of the underside is olive-green without streaking.
Wing bars are absent.
Similar to the breeding female. Similar to the female. The bill is thinner and the eye is dark, not red. Females and fall individuals resemble the Orange-crowned Warbler. However the breast of the Orange-crowned Warbler is lightly streaked.