changeable

adj

1. Capable of being changed.
2. Subject to sudden or frequent changes.

   “The weather is very changeable today: we've had bright sunshine, clouds, wind and rain in the same half-hour.”

   “There will be no problems with visibility, or the highly changeable Highland weather, as Scotland basks in what is reported to be the country's hottest September day for more than a century.”

3. Capable of camouflaging itself by changing colour.