Elachista nubila is a moth of the Elachistidae family that is endemic to Arizona. The length of the forewings is 4–4.9 millimetres (0.16–0.19 in). The forewings are broad, grey and densely dusted with light brown scales especially along the costa and in the distal half of the wing. The hindwings and underside of the wings are grey. Females are larger and have paler forewings, varying from dirty yellowish white to light greyish brown.