The Puget Sound region is bracing for the arrival of a marine layer, a common meteorological event that brings cooler temperatures and increased cloud cover. This phenomenon occurs when moist air from the Pacific Ocean moves inland, frequently causing foggy conditions and reduced visibility, especially during the night and early morning hours. Residents should anticipate a noticeable drop in temperatures, with daytime highs likely to remain below average for this time of year. The National Weather Service is urging motorists to be cautious due to potential visibility issues, particularly during the morning commute, and advising boaters to adjust their navigation accordingly.