Missouri – Headlights blur through pockets of fog early this morning as mild air settles over eastern Missouri. Pavement feels damp, visibility drops quickly, and the calm start hides a sharp shift coming before the new year.
According to the National Weather Service, a Dense Fog Advisory remains in effect for parts of the St. Louis metro early today. Visibility may drop below a quarter mile at times, especially along I-64, I-70, and I-55. Drivers should slow down through the morning and allow extra stopping distance.
Fog lifts by mid-morning, revealing unseasonably warm air. Afternoon temperatures climb into the upper 60s, nearly 10 degrees above normal for late December. Travel improves through the afternoon, with dry roads and light winds helping weekend plans.
Tonight stays mild, with lows near the mid-40s. Saturday follows a similar pattern, featuring filtered sunshine and highs again near the upper 60s. For now, holiday travel conditions remain favorable across eastern Missouri and southwest Illinois.
Changes arrive Sunday. Clouds thicken early, followed by periods of rain through the day. Some showers may turn briefly heavy, and a rumble of thunder cannot be ruled out. Wet pavement could slow traffic during peak travel hours. Temperatures peak near the low 70s before colder air pushes in late.
By Sunday night, rain may briefly mix with snow as temperatures drop rapidly. While accumulation appears limited, the quick cool-down raises concern for flash freezing on untreated roads. Slick spots could develop before sunrise Monday.
Monday brings full winter back. Skies clear, winds turn brisk, and highs struggle to reach the upper 20s. Any leftover moisture freezes solid. Monday night dips near 20 degrees, reinforcing icy conditions.
Looking ahead to New Year’s Eve on Wednesday, dry weather holds with highs near the upper 30s. Cold air lingers, but travel conditions appear quiet. Until then, plan around fog early, rain Sunday, and a fast-moving winter snap to close out 2025.
Driving today or Sunday? Tell us what conditions you’re seeing on your route.
Five-Day Outlook for St. Louis, MO
Today: Morning fog, then partly sunny. High near 68°.
Saturday: Partly sunny and mild. High near 68°.
Sunday: Rain, possible thunder. High near 71°.
Monday: Sunny but cold. High near 29°.
Tuesday: Mostly sunny. High near 36°.
