Huge explosion at oil depot in Hertfordshire this morning, visible by satellites, and (due to temperature inversion) audible far off. I did hear something betwen 6am and 6.30 - assumed it was the neighbours.

Said temperature inversion presumably responsible for low mist under clearish sky with bright sun. in the afternoon a 'sparkling mist', which cleared in time for an almost-daylight Venus Observed at 3.36pm.

0830. Low mist, clear with Ci above
1100. Straight halo seen.
Mist returned in afternoon.
1536. Venus observed.