Do you have galvanized steel plumbing? If so, some of the pipes in your home may be obstructed with corrosion deposits - limiting the flow of water. If you have a drop in pressure at a specific faucet, check the screen on the spigot, it may be filled and slowing the stream of water.
Is the pressure at neighboring residences also low? If so, contact the Utility at 414-371-3080. There may be a main break in your area temporarily reducing pressure in your neighborhood.