Chicago weather: Heat peaks this weekend with triple-digit heat index possible

Chicago weather: Thursday morning forecast

FOX 32's Mike Caplan breaks down today's weather outlook.

CHICAGO - We are 74 days into meteorological summer. Roughly 70 percent of those days have had at-or-above-normal temperatures. The next surge of hot and humid weather is in sight and will peak this weekend. 

Chicago weather forecast

What to expect:

Today looks gorgeous with sunshine, lower humidity and highs in the mid 80s like yesterday. It will be a couple of degrees cooler right along the lake. Tonight will be clear and pleasant with lows in the upper 60s and low 70s. 

Tomorrow should easily reach 90° and possibly a couple of degrees more. There will be plenty of sunshine and an uptick in humidity. 

The first gray area in this forecast cycle will be the possibility of thunderstorms sneaking in from the north Saturday morning. If these hold together, there will be an impact on temperatures that day as well. If they fall apart, the impact will be far less. Either way, it looks like highs on Saturday could reach the mid 90s with the heat index very likely in triple digits. 

On Sunday, there is a similar chance for a cluster of thunderstorms to move in during the morning. Highs on Sunday will once again be in the low to mid 90s. 

On Monday it will likely reach 90° for the fourth day in a row with partly sunny skies and a chance of thunderstorms mainly at night. 

Tuesday we have scattered showers and storms and it will not be as hot with highs in the low 80s.