ST. LOUIS — Summer temperatures kick in starting today, with highs in the low 90s. the humidity remains on the lower side so the heat index will not be a big factor today.
That changes somewhat on Thursday as both temperatures and humidity increase. Afternoon highs Thursday will soar into the mid-upper 90s with a top heat index approaching 100.
A weak front will initiate a band of scattered strong to severe storms Thursday evening over far northeast Missouri into central Illinois. These storms will build south and west during the late evening and into the night. The storms will be strongest far north of St. Louis, where there is a Level 2 (out of 5) risk of damaging winds and large hail. The storms will be weakening as they approach I-70.
The timing for these storms will be from 9 p.m. to midnight Thursday night. If they last, they would reach metropolitan St. Louis around midnight. The fading storms will then drift south-southwest across the rest of the region after midnight and be gone before sunrise.
Mid-summer heat and humidity will continue even after the Thursday night storms. Daily high temperatures will range from 90 to 95 on Friday and Saturday and soar into the upper 90s for Father’s Day. At this time, temperatures appear to be below record levels.
Record highs for late this week are as follows: Wednesday (98 in 2016), Thursday (100 in 2022), Friday (99 in 2022), Saturday (101 in 1952 ), and Sunday (100 in 1950). The heat index will peak in the 100 to 105 range this weekend, especially Sunday.