Knox County woke up Monday, April 27, 2026, to patchy fog, near-soupy humidity, and temperatures hovering around 54°F. That murky start will give way to a mostly sunny, warm day, with highs near 83°F and light southwest breezes. The pleasant stretch will not last long, though, as forecasters are calling for two rounds of showers and thunderstorms: one late Monday night into Tuesday, and another from Tuesday night into Wednesday.
Afternoon Heat, Evening Showers
Through the afternoon, expect plenty of sunshine and unseasonably warm air, with highs near 83°F and southwest winds generally around 0 to 5 mph. Clouds will thicken overnight. After midnight into the early hours of Tuesday, April 28, a brief round of showers may roll through, followed by a better chance of showers and thunderstorms later in the night. Rainfall totals from this first batch should stay on the lighter side for most neighborhoods, roughly one-tenth to one-quarter of an inch.
Tuesday Through Wednesday
Tuesday, April 28, keeps the warm theme going, with highs near 77°F and a much higher shot at storms. Showers and thunderstorms are likely before 2 p.m., with southwest winds increasing to 5 to 15 mph. Stronger cells could kick up gusts as high as 25 mph.
A second, more widespread round of showers and storms late Tuesday night into Wednesday could pack a heavier punch. Rainfall totals in this window may reach a quarter to a half inch, accompanied by gusty winds. Forecasters note that foothills and Plateau areas could see gusts up to about 40 mph, so it will be a blustery stretch for higher terrain. These details come from the National Weather Service in Morristown.
Commute and Safety
Drivers can expect a mostly dry Monday evening commute, but early-morning travelers should be ready for lingering low clouds or fog, especially near Oak Ridge and in valley low spots. When storms arrive overnight and again Tuesday night, heavy downpours may quickly cut visibility and cause brief ponding on low-lying roads. Slow down, give yourself extra stopping distance, and avoid driving through standing water.
Residents in hillier and more exposed areas may want to secure trash cans, lawn furniture, and other loose outdoor items ahead of the gustier periods, and be prepared for sudden wind bursts with the stronger storms.
Looking Ahead
Once the Wednesday system moves on, cooler air settles in. Thursday, April 30, looks mostly sunny with a high near 67°F and overnight lows dipping into the mid-40s. Rain chances ease toward the end of the week, with only isolated showers expected Friday into the weekend as highs level off in the upper 60s.
This heat-and-storm pattern has been on our radar since last week. For more context, see our April 22 update and earlier heat-and-storm outlook.
