A crisp chill lingers over central Iowa this morning, but the real concern builds as skies clear and temperatures prepare to plunge again, setting up a widespread frost threat that could quietly damage plants and impact early travel.
According to the National Weather Service, a Frost Advisory is in effect from 1 a.m. to 8 a.m. Saturday across Des Moines, Ames, Ankeny, and Marshalltown, with temperatures falling into the 32°F to 36°F range.
This is part of a broader system dragging much-below-average temperatures across the Midwest, keeping early May conditions unusually cold.
Light showers may pass through this afternoon, especially east of I-35, briefly dampening roads in Des Moines and Newton. As clouds clear later, rapid cooling sets in. That shift allows frost to develop quickly in low-lying areas like river valleys and rural fields surrounding Polk and Story counties.
The main impact centers on vegetation. Early gardens, flowering trees, and crops face damage if left uncovered. Urban heat may limit frost in downtown Des Moines, but suburbs and open farmland remain vulnerable.
Drivers should also watch for isolated slick spots early Saturday. Moisture left on bridges and overpasses along I-35 and I-80 could briefly freeze, creating patchy hazards before sunrise.
Looking ahead, temperatures rebound fast. Sunshine returns Saturday afternoon with highs in the mid-60s. By Sunday and Monday, a warming trend pushes highs into the 70s, with a chance for scattered thunderstorms developing into early next week. Severe weather potential remains low for now, but a few stronger storms could emerge by Sunday evening.
Five-day outlook:
Saturday: Early frost, then sunny, high near 64°F
Sunday: Warmer, high near 74°F
Monday: Mild, high near 79°F with isolated storms
Tuesday: Chance of showers, high near 63°F
Wednesday: Partly sunny, high near 60°F
