Looks like that minor frontal feature shown on the Met Office charts
has just passed over the Southampton area. There appears to be a trace
amount of rain associated with it, but more notable is the "day gloom"
which has reduced light levels typical to those of sunset and turned
lighting on the exterior of a nearby building on, around 15 mins ago,
more than an hour before sunset and earlier, relative to sunset, than
any recent wet evenings. Seems to be clearing from the northwest now.

Nick