Earlier in the day Andy C and myself had decided it looked like being a good night for Noctilucent Clouds and much to our surprise we turned out to be correct. By the time I arrived at our chosen observing spot at Aidan's College at around 00:30 BST the display was at its height. We estimated a brightness of around 4 and definite structure throughout the display that extended upwards to around 20 degrees and covered about 60 degrees of sky in a North to North Westerly direction with the brightest region concentrated around and below the bright star Capella in
After we left Aidan's at around 01:30 I went on a brief tour around Durham, getting some beautiful views down by the river, and then up above the city. By this time (around 02:30) the display had visibly diminished to a veil type but with slight patches of the earlier structure still visible high up.
It was a lovely night and the first spectacular display I've seen this season.