(9:00PM Sun, Aug 20th 2023) Sunday update regarding a strong and large ridge that has developed across the region, bringing a period of of hot and humid conditions across the state. These conditions are expected to continue for a multi-day period, from through late this upcoming week.

Update…
With this update little to no changes were needed with daily forecasts, as things are on track based on the latest model guidance.

Timing & Location…
•Mon, Aug 21st: Northwestern, Central & Southern Illinois.
•Tue, Aug 22nd: All of Illinois.
•Wed, Aug 23rd: All of Illinois.
•Thur, Aug 24th: All of Illinois.
•Fri, Aug 25th: Northwestern, Central & Southern Illinois.

Impacts…
•Mon, Aug 21st: High temperatures of 89-98 across Northwestern, Central and Southern Illinois, with peak heat indices of 95-117.
•Tue, Aug 22nd: High temperatures of 89-98 across all of Illinois, with peak heat indices of 95-117.
•Wed, Aug 23rd: High temperatures of 93-102 across all of Illinois, with peak heat indices of 100-117.
•Thur, Aug 24th: High temperatures of 94-104 across all of Illinois, with peak heat indices of 100-117.
•Fri, Aug 25th: High temperatures of 89-101 across Northwestern, Central and Southern Illinois, with peak heat indices of 95-113.