The fog was thick all the way until I was close to my destination. Suddenly there was a break in the fog, and I could see Conic Hill in sunshine.
I soon climbed into the sunshine, but the fog then rose and hid the view until I was at almost exactly 300m. Suddenly it cleared again and the sun shone. I was soon on the summit ridge, and as the sun cleared I saw a glory - a ring of rainbow colours - on the cloud below me.
To the west, Loch Lomond was covered in cloud, though one of the islands was peeping through.
To the south, the Campsies were sticking up out of the fog.
The fog rose again and the glory became stronger, showing my shadow, the Brocken spectre, at the centre.
The mist was still swirling round the summit.
To the north, the fog cleared off the summit of Ben Lomond.
Soon it came rolling back up the glen below me.
I went to the west end of the ridge. Normally this is a good viewpoint for seeing the Highland Boundary Fault stretching across Loch Lomond, but this was blotted out by the fog which was rising and falling below me.
I stayed on the summit ridge for several hours, as I didn't want to go back down into the fog. Then I began the descent.
There was still some frost on the vegetation in places.
I had a last clear view back to the summit, with another Brocken spectre in the foreground.
I noticed that there was also a fogbow, which is just visible in the picture below.