Mackerel sky?

This morning we visited  my Mum, and took her out for coffee, which was all very pleasant.
This afternoon  we did more work in the garden, planting up containers with Violas and Cyclamen, tidying the shed, and potting on some lavender cuttings. 
It's been very warm  and sunny again, but while I think this evening's  sky may suggest change is on the  way, the BBC say otherwise. I wonder who will be right?