This happened last weekend in Sydney.

The sky was clear until this streaky mist began to form in the afternoon.

The visuals are quite striking, but there are two sides to this mystery that I would like to point out;

Firstly, it was a very warm day for July, so it could have been a natural occurrence.

Secondly, for my fellow cloud-seeding conspiracy theorists, there was a plane up there emitting a trail that DID NOT register on flight tracking apps.

Both photos were taken at Northmead, NSW on Saturday 15th July at 2:30pm.