Grand Marais, Minn. – Gardeners and early risers in northeastern Minnesota woke up to freezing temperatures Saturday morning as a frost advisory remains in effect until 9 a.m. for Cook and Lake Counties, including Grand Marais, Isabella, and the Grand Portage Reservation.
According to the National Weather Service in Duluth, overnight lows dropped to near 30 degrees, creating conditions ripe for widespread frost formation across the Boundary Waters eastern and central areas. Sensitive plants and unprotected gardens are at risk of damage or even death if left exposed.
The advisory affects both Northern Cook and Lake and Southern Cook counties, with especially chilly pockets near inland forested zones. Residents are urged to cover plants or bring them indoors if possible. While short-lived, these sub-freezing temperatures are unseasonably cold for mid-June and could come as a surprise to campers and visitors in the Boundary Waters.
Temperatures are expected to rise steadily after sunrise, reducing the threat by late morning. No additional frost advisories are in effect beyond 9 a.m. today, but early summer visitors should monitor conditions overnight in higher elevations or shaded valleys.
