Light Rain Arrives as Weak Front Moves Into Southern Oregon, Northern California

MEDFORD, Ore. (Nov 23, 2025) – Fog lifted across west side valleys Sunday as mid-to-high-level clouds pushed into southern Oregon and northern California ahead of an approaching weak front, according to the National Weather Service.

Forecasters say the system will bring light coastal rainfall tonight, with inland showers west of the Cascades expected into early Monday morning. Rainfall amounts are expected to be modest — coastal ranges may see 0.2 to 0.4 inches, while west side valleys will likely remain below 0.2 inches. Snow levels holding at 6,000 to 7,000 feet will keep any snowfall limited to high peaks and ridgelines. Cascade passes may also see 0.2 to 0.4 inches of precipitation, with only isolated showers extending farther east.

Behind the front, forecasters expect generally quiet weather through midweek. A weak warm front and onshore flow will bring slight shower chances — 10% to 30% — to northern Coos, Douglas, and Klamath counties Tuesday and Wednesday. Additional showers may drift inland west of the Cascades on Thursday as a shortwave trough passes to the north, though any rainfall would likely measure only in the hundredths of an inch.

Cloud cover is expected to persist through the week, which may reduce daytime heating and overnight cooling. With those factors decreasing, fog formation may be less likely. Temperatures are forecast to warm 5 to 10 degrees above seasonal norms on Wednesday and Thursday.

A low-pressure system is expected to drop south from Canada into the continental U.S. on Friday and through the weekend. While precipitation chances remain uncertain and dependent on the system’s track, early ensemble guidance does not indicate any high-confidence hazardous outcomes. A cooling trend, however, appears likely as northerly flow ushers in colder air.

Daytime highs are forecast to remain near seasonal averages, but overnight lows will fall beginning Friday night. By Sunday night into Monday morning, coastal areas could reach the low 40s to mid-30s, while most west side valleys may dip into the mid-20s. The Umpqua Valley may stay slightly warmer, in the low-30s. East of the Cascades, forecasters say mid-teens to single-digit lows are possible.