Portland, OR – A Frost Advisory is in effect for Portland and surrounding areas tonight through Wednesday morning, as clear skies and calm winds create ideal conditions for widespread frost across northwest Oregon and southwest Washington, according to the National Weather Service in Portland.
Frost Advisory Details
The advisory will be in effect from midnight to 9 a.m. Wednesday, October 14, 2025, covering a number of regions including:
- Lower Columbia River region
- Tualatin Valley
- Benton County lowlands
- Cascade foothills of Marion and Linn Counties
- Inner Vancouver Metro and North Clark County lowlands
Overnight Temperatures Expected to Dip
Forecasters are warning that overnight lows could drop into the low 30s, which may damage or kill sensitive plants if left uncovered. Residents are urged to move potted plants indoors or cover outdoor vegetation with lightweight blankets or fabric for added protection from the cold.
Frost Formation and Impact
The National Weather Service notes that frost formation will be widespread, particularly in rural and low-lying areas, where cold air tends to settle overnight. With clear skies and light winds, conditions will be ideal for the frost to form, impacting sensitive plants and vegetation in affected areas.
Warmer Temperatures Expected by Afternoon
By late morning on Wednesday, temperatures are expected to rebound, with sunshine returning throughout the afternoon. However, the brief cold snap will have potentially significant impacts on outdoor plants and gardens in the meantime.
Are you prepared for tonight’s frost? Share how you’re protecting your plants in the comments below.
