With record high temperatures and dew points in the 70s, dangerous heat index values in excess of 105 degrees are expected Sunday. The anticipated abundant sunshine will add another 5 to 15 degrees to this apparent temperature making for extremely dangerous conditions for those participating in outdoor activities or spending any time at all in the sun. Take extra precautions to stay cool in shady areas and look out for those most vulnerable to heat.
Sunday will mark the second consecutive day with afternoon temperatures reaching mid to upper 90s – if we hit our forecast high of 98 degrees, it will establish a new record high for this date exceeding the old record of 96 degrees back in 1957 and also be hottest Father’s Day on record beating the 95 degrees back on June 20, 1971.
Another very important factor to keep in mind is that overnight low temperatures in the “Chicago Heat Island” will probably not drop below 80 degrees both Saturday and Sunday night, allowing little or no relief from the incessant heat. This was a very important factor in the disastrous 1995 Chicago heat wave.