Weather
Delaware Weather Oct. 17–21: Frost Possible Sunday Morning
Wilmington, DE – Northern Delaware faces a sharp autumn cooldown this weekend, with patchy frost possible around Wilmington early Sunday as temperatures fall into the upper 30s following Friday's rain
By Marcus Hale · 2026-10-14T08:35:52.575Z
Wilmington, DE – Northern Delaware faces a sharp autumn cooldown this weekend, with patchy frost possible around Wilmington early Sunday as temperatures fall into the upper 30s following Friday's rain and a significant drop in daytime warmth.
According to the National Weather Service in Mount Holly, New Jersey, Wilmington temperatures are expected to reach approximately 55 degrees Saturday before dropping to around 38 degrees overnight. Patchy frost is specifically included in the forecast for Saturday night and Sunday morning.
The colder conditions follow a stretch of unusually warm weather, including a forecast high near 85 degrees Wednesday and another surge to 79 degrees Friday.
Friday Rain Precedes Sharp Weekend Cooldown The transition begins Thursday night, when showers become likely after 2 a.m., with precipitation chances reaching 70%.
Friday brings additional showers, with thunderstorms also possible after 5 p.m. The National Weather Service places the precipitation probability at 90%, with southwest winds of 10 to 15 mph.
Rain and possibly a thunderstorm could continue Friday evening before precipitation chances decrease overnight. Breezy conditions are also expected Friday night.
By Saturday, sunshine returns, but temperatures will struggle to reach the mid 50s, approximately 24 degrees below Friday's forecast high.
The cooler weather will be especially noticeable Saturday night, when mostly clear skies accompany temperatures approaching the upper 30s.
Patchy Frost Expected Sunday Morning The National Weather Service specifically forecasts patchy frost around Wilmington Saturday night and before 9 a.m. Sunday.
Although temperatures are expected to remain above freezing at the Wilmington forecast location, frost can develop when air temperatures fall into the 30s, particularly in colder or sheltered areas.
Sensitive outdoor plants could be vulnerable, making Saturday evening an important time for gardeners to take precautions.
National Weather Service frost and freeze guidance recommends bringing vulnerable plants indoors or protecting them with lightweight coverings when necessary.
The supplied forecast does not indicate an official Frost Advisory or Freeze Warning for Wilmington.
The colder conditions should ease relatively quickly, with temperatures recovering into the lower 60s Sunday and continuing to climb early next week.
By Tuesday, Wilmington could approach 70 degrees as milder weather returns.
Five Day Weather Outlook: Oct. 17–21 Temperatures below represent National Weather Service forecasts for Wilmington, Delaware, illustrating conditions in northern Delaware. Temperatures elsewhere in the state may vary.
Saturday, Oct. 17: Sunny and cooler, with a high near 55°. Mostly clear overnight, with a low around 38°. Patchy frost possible overnight. Sunday, Oct. 18: Patchy frost before 9 a.m., then sunny, with a high near 61°. Mostly clear overnight, with a low around 41°. Monday, Oct. 19: Sunny and warmer, with a high near 66°. Partly cloudy overnight, with a low around 47°. Tuesday, Oct. 20: Partly sunny, with a high near 69°. Overnight temperatures were not provided.