East Tennessee Weather: Sizzling Sunday-Funday Kicks Off Heat Wave Week

Happy Sunday-Funday, East Tennessee!
On this glorious Sunday, June 22, 2025, at 8:59 AM EDT, we’re basking in the heart of summer with warm mornings, scorching afternoons, and the perfect excuse to hit the water. The heat wave that began this weekend intensifies, with highs in the low to mid-90s and heat indices pushing 100°F today, climbing toward heat advisory criteria by midweek. From the lively streets of Knoxville to the misty trails of the Great Smoky Mountains and the vibrant riverfront of Chattanooga, the EastTNweather platform, led by meteorologist Mike Witcher, delivers hyper-local updates via its app, website, YouTube, Roku, Amazon Fire, and Apple TV to keep you weather-ready. 

Sunday: Warm Mornings, Hot Afternoons, and Water-Perfect Weather
Sunday-Funday starts warmer than yesterday, with morning temperatures in the 60s to low 70s across East Tennessee, accompanied by dew points in the low 70s, creating a sticky but classic summer feel. Patchy fog may linger in low-lying areas like Sevierville, Cleveland, or along the Tennessee River near Chattanooga, but it burns off quickly, giving way to mostly sunny skies. By lunchtime, temperatures climb to the 80s, with afternoon highs reaching the low to mid-90s, about 10-12 degrees above the seasonal average of 81°F. The heat index pushes near 100°F in valley locations like Knoxville, Chattanooga, and Athens, while the Cumberland Plateau and Smoky Mountains see slightly lower values, around 95°F.

Fair weather cumulus clouds build after noon, and a few may spark isolated afternoon showers or storms, particularly in the Smoky Mountains near Gatlinburg or Cherokee, or south of I-40 in Chattanooga and Cleveland. Rainfall will be minimal, under 0.25 inches, keeping the day mostly dry and ideal for outdoor fun. The EastTNweather app is your go-to for tracking any stray storms, with its Interactive Radar offering past, current, and two-hour future projections. Seize the day for water-based activities like kayaking on the Tennessee River in Chattanooga, swimming in the Smoky Mountains’ streams, or boating on Fort Loudoun Lake in Knoxville. Check the app for storm alerts and enjoy this perfect summer day!

Next Week: Heat Wave Intensifies with Daily Storm Chances
The heat wave strengthens through the week, with highs in the low to mid-90s and lows in the 60s to 70s. Dew points in the low 70s push the heat index to 100-105°F, nearing or meeting heat advisory criteria (105°F) by midweek, especially in valley areas like Knoxville, Chattanooga, and Cleveland. The Cumberland Plateau and Smoky Mountains will also feel the heat, with heat indices around 95-100°F. A strong ridge of high pressure, shifting slightly toward the Eastern Seaboard, maintains hot and humid conditions, fueling classic summertime afternoon storms daily from Monday through Friday. These storms, driven by heat and humidity, may bring brief heavy rain (0.25-0.5 inches per day), particularly south of I-40, but are unlikely to be severe. North of I-40, including Morristown and the Tri-Cities, expects spottier showers.

The EastTNweather app’s extended forecasts will track this heat wave and daily storm chances, with alerts for heat advisories or localized flood risks. The platform’s streaming updates on YouTube, Roku, Amazon Fire, and Apple TV, led by Mike Witcher, provide context for planning around the heat and storms. Schedule water activities like visiting splash pads in Chattanooga or swimming in Pigeon Forge, but plan indoor tasks in Knoxville or Morristown during peak storm hours (2-6 PM). The high UV index demands high-SPF sunscreen and protective clothing for outdoor events in Athens or Cleveland. Stay tuned to the app for updates, ensuring your summer plans stay safe and vibrant.

Rainfall Outlook: Light This Week, Increasing Midweek
Over the next seven days, rainfall totals will range from 0.5-1.5 inches across East Tennessee, with most rain coming from daily afternoon storms starting Monday. South of I-40, including Chattanooga, Cleveland, and Athens, may see 1-1.5 inches, while north of I-40, like Knoxville and the Tri-Cities, expects 0.5-1 inch. Areas hit by repeated storms could see slightly higher totals, raising localized flood concerns in urban areas like Knoxville’s downtown or near rivers like the Little Pigeon in Sevierville or the Hiwassee in Cleveland. The EastTNweather app’s Interactive Radar and flood alerts are essential for monitoring rain, especially in flood-prone areas. Check the app daily to stay ahead of potential flooding and plan accordingly.

Heat Safety Tips for East Tennessee
With highs in the low to mid-90s and heat indices nearing 105°F, heat safety is critical, especially as our bodies adjust to summer’s intensity. The high UV index also increases sunburn risks, making precautions vital. Here are key tips to keep you, your family, and your neighbors safe:

• Stay Hydrated: Drink water regularly, even if not thirsty, and avoid alcohol or sugary drinks during outdoor activities in Knoxville or Chattanooga to prevent dehydration.
• Protect Against Sunburn: Apply high-SPF sunscreen (30+), reapplying every two hours, and wear hats, sunglasses, or UV-protective clothing for lake trips in Cleveland or hikes in the Smoky Mountains.
• Take Breaks: If working outdoors in Sevierville or Athens, take frequent shade breaks and avoid strenuous activity from 10 AM to 4 PM, when heat peaks.
• Check on Vulnerable Neighbors: Visit elderly or at-risk neighbors in Chattanooga or Cleveland, ensuring they have access to air conditioning or cooling centers during the 100-105°F heat index.
• Know Heat Illness Signs: Watch for dizziness, nausea, or rapid heartbeat, signaling heat exhaustion or heat stroke. Seek immediate medical help if symptoms appear.
• Plan Water-Based Fun: Beat the heat with swimming at Ijams Nature Center in Knoxville, kayaking in Chattanooga, or visiting pools in Pigeon Forge. Check the EastTNweather app for storm-free times.