Portland, Oregon – Gardeners and growers across western Oregon and southwest Washington should brace for a chilly night Monday, as a widespread frost advisory goes into effect from midnight to 9 a.m. Tuesday. Temperatures dipping as low as 33°F could damage unprotected outdoor plants.
According to the National Weather Service in Portland, the advisory includes the central and southern Willamette Valley, Tualatin Valley, Lower Columbia River, and Cascade foothills, along with parts of southwest Washington such as Cowlitz County and the South Washington Cascade Foothills.
Cities like Portland, Eugene, Hillsboro, Salem, and Longview are among those at risk for frost formation, especially in lower-lying or sheltered areas. Residents are advised to cover sensitive plants with light cloth or move potted plants indoors before temperatures drop.
This late-April cold snap is unusual but not unprecedented. Similar frost events have occurred in previous springs, particularly in elevated valleys or coastal ranges. Frost may return early Wednesday depending on overnight cloud cover.
Frost advisories remain in place through 9 a.m. Tuesday. Further updates may follow if temperatures remain near freezing midweek.
