Heat index 118 degrees on July 5 in county

Union County residents had a bit of a break during the past week from recent sweltering summer heat and humidity.

On July 5, the heat index in Jonesboro reached nearly 120 degrees.

However, by early this week, extreme heat and humidity once again were blanketing Southern Illinois, Southeast Missouri and Western Kentucky.

The National Weather Service office in Paducah reported that on Tuesday, July 10, heat index readings in the region were expected to reach 102 to 105. A high temperature in the low to mid 90s was in the forecast for Tuesday afternoon.

The heat index is a way to measure how hot it feels when humidity and air temperature are taken into consideration.

During extreme heat, the weather service advised area residents to:

Take frequent breaks in air conditioning. Drink plenty of water. Check on those without air conditioning or in poor health. Never leave a child or pet in a vehicle under any circumstance, especially during hot weather, when vehicle interiors can reach lethal temperatures in minutes.

The weather service reported that upper level high pressure set up across the region to end the month of June and lasted through the 4th of July holiday weekend.

This resulted in high temperatures routinely reaching into the low to mid 90s in the region.

“Oppressive humidity levels were in place much of the time as well,” the weather service noted.

This resulted in daily heat index readings of 100 degrees or above for seven straight days.

The most intense heat and humidity occurred on July 5, when high temperatures reached into the mid to upper 90s and heat index readings soared to between 110 and 115 across much of the region.

118-Degree Heat Index

Local weather observer Dana Cross recorded a heat index reading of 118 degrees at 4 p.m. on July 5 in Jonesboro. By 6 p.m., the heat index had dropped to 116.4 degrees.

On July 4, the heat index reading was 116.5 degrees at 7 p.m. in Jonesboro.

Cross said that during the extreme weather, heat index values had climbed into the 100s by 11 a.m., and stayed that high into the evening hours. 

On July 4, the heat index had climbed into the 100s by 9 a.m. The reading did not drop out of the 100s until 8:30 p.m. 

Maximum heat index readings for other communities in the region on July 5 included:

107 in Cape Girardeau. 109 in Carbondale. 114 in Paducah. 113 in Poplar Bluff, Mo. 110 in Cairo. 112 in Metropolis. 112 in Harrisburg. 113 in Carmi. 110 in Marion. 115 in Trenton, Ky.

Weather for June 26 through July 9

During the period of June 26 through July 9, the high temperature in Jonesboro was 97. The low for the period was 64. 

Precipitation for the period totalled 4.12 inches, including 2.53 inches on June 26, .38 of an inch June 27, 1.15 inches on June 28 and .06 of an inch July 6.

Following are temperatures for the period as recorded by official weather observer Dana Cross in Jonesboro:

                                  H   L

Tuesday, June 26       89 67

Wednesday, June 27   90 66

Thursday, June 28       89 69

Friday, June 29           92 66

Saturday, June 30       94 74

Sunday, July 1            93 73

Monday, July 2           91 72

Tuesday, July 3          92 72

Wednesday, July 4      96 73

Thursday, July 5         97 72

Friday, July 6              89 73

Saturday, July 7          83 66

Sunday, July 8            89 64

Monday, July 9           92 69