Possible Clues:

• Most dreary, in Dublin
• Most overcast, in London
• The answer to this clue is the least interesting
• Gross things that look ultimately at least interesting
• Most white, egrets flying across end of estuary
• Most gloomy feature of ogre? Yes, thankfully
• Engineers certainly blocking sports car that's far from exciting
• Yet Reg's prepared to become most gloomy
• Cloudiest, in England
• Most dull, in Dover