Possible Clues:

• Thirty-one days, just in one part of capital
• Type of blossom just in one area of London
• Fashionable London neighborhood
• Tree fine in this part of London
• Is this the London equivalent of 1 across?
• Go after this London location
• Central London area
• 400 Monopoly property
• Monthly weather report in London
• Upscale London district