All those lovely galaxies in Leo, Virgo and Coma are still well placed this month, but as the sun moves north the period of dark skies available to see them is diminishing. 10.30 pm BST is the earliest practical time for viewing them at the beginning of the month. It will be an hour later by the end.
Saturn comes to opposition on the 10th, but an opposition at this time of year means it is very low in the sky ( in Libra) for UK observers, but on a good night with a middling size telescope you should be able to see some detail (Cassini’s Division at least) on the rings, a few of the moons, and perhaps some cloud detail.
This is also a good time for observing all 3 of the main night time planets together – as dusk falls Jupiter is sinking in the west, Mars is (relatively) high in the south, and Saturn rising in the east. Quite a good time to compare size, brightness, colour, and visible detail on each of them.
I have also seen predictions of a possible new meteor shower on May 24 as the earth passes through the orbital track of a small (but nearby) comet, 209P/LINEAR. Meteor showers are even more unpredictable than comets, but I’ll be watching out that night if the skies are clear.