still in doubt; "an unsettled issue"; "an unsettled state of mind"

lacking order or stability; "these unsettled times"

To present participles which come from intransitive verbs, or are themselves employed as adjectives, to mark the absence of the activity, disposition, or condition implied by the participle;

Changeable, variable (Oxford Dictionary).

subject to change; "a changeable climate"; "the weather is uncertain"; "unsettled weather with rain and hail and sunshine coming one right after the other"

A period of variable and uncertain weather.

A term used to describe when earth geomagnetic fields are unsettled.

With regard to geomagnetic activity, a descriptive word defining conditions between quiet and active, specifically meaning that the A index is between 8 and 15.

not settled or established; "an unsettled lifestyle"

not yet settled; "unsettled territory"