Louisville is heading into Sunday with light or calm winds overnight, while scattered mid-level clouds could develop Sunday afternoon before clearing Sunday night. The easy morning setup will give way to low 90s in the afternoon. The bigger story is a long stretch of dangerous heat building across the region through the middle of the week.
The National Weather Service office in Louisville expects mostly sunny skies Sunday, with possible scattered mid-level clouds developing in the afternoon before clearing Sunday night, light or calm winds overnight and possible afternoon gusts around 20 mph. Humidity may ease a bit during the afternoon, but the heat index could still reach the mid to upper 90s, making outdoor plans feel considerably hotter than the thermometer suggests, the National Weather Service reported.
Midweek Heat Could Push Heat Index Over 100
Monday will be mostly sunny, with temperatures gradually increasing through Thursday. Wednesday and Thursday are expected to bring 90-degree-plus temperatures, with warm overnight lows in the mid to upper 70s offering limited relief. According to the National Weather Service Louisville climatology page, 1991-2020 monthly, seasonal and annual temperature normals are available for comparison with the current forecast.
Forecasters say heat index values have a 60% to 80% chance of exceeding 100 degrees from Tuesday through Thursday. No local watches, warnings or advisories are listed Sunday morning, but heat-related headlines will likely become necessary as the hot pattern persists.
A comparable past episode came on 20 Jul 2017, when Louisville Metro Government officials urged caution as the heat index was forecast to reach between 100 and 105 on Thursday and Friday. Louisville Metro Government cites a study by Dr. Stone stating that heat-related ailments contribute to the deaths of 86 Louisville residents each year.
Storm Chances Return Late In The Week
Friday should remain mostly sunny and hot, with a high near 95 and a 30% chance of precipitation. Saturday brings a slight chance of morning rain, followed by a chance of showers and storms during the afternoon, with temperatures topping out near 92.
Sunday's light winds will generally come from the south. Anyone spending extended time outdoors should plan around the afternoon peak, drink water regularly and take breaks in air conditioning or shade, especially as the heat builds Tuesday through Thursday.
