Oregon wakes to a thick blanket of overcast sky as Portland’s streets shine with damp pavement and cool December air. Wisps of fading fog cling to low spots along the Columbia River, and the morning feels heavy and still—an early hint of the pattern building into the weekend. Drivers moving before sunrise may notice shifting visibility, especially near open fields and river-adjacent corridors.
According to the National Weather Service, patchy fog may redevelop after 5 p.m. today, followed by patchy dense fog late tonight into early Saturday. These quick visibility drops could slow travel along I-5, I-205, and the Sunset Highway. Calm winds will keep fog pooling in the valley floor, creating pockets of low visibility that appear without warning.
Meteorologists are now tracking a more active Pacific system expected to reach Portland late Saturday night, bringing a 60% chance of rain, followed by a stronger wave Sunday where rain becomes likely through the day. To be fair, rainfall amounts may start light, but soaking showers will dominate Sunday afternoon and persist into Monday and Tuesday. This early-December shift highlights the region’s transition into the wettest stretch of the year.
Temperatures remain mild, with highs near 56° today and 56–57° through Sunday, but the added moisture could trigger frost patches overnight in rural pockets where skies briefly clear.
Conditions may deteriorate fast once rain bands arrive Sunday, and standing water may form on busy corridors. Keep extra driving time and watch for slick areas.
Five-Day Outlook
Saturday: Fog early, then sunny, high 56°.
Sunday: Rain likely, high 55°.
Monday: Rain, high 69°.
Tuesday: Rain, high 52°.
Wednesday: Rain likely, high 50°.
