Excessive Heat and Humidity July 4-8, 2022

Overview

A strong upper level ridge of high pressure built into the lower Ohio Valley on the 4th of July and remained in place until a cold front provided relief from the heat late on July 8th. The most oppressive days were July 5 and 6. High temperatures in the mid 90s to around 100 combined with extremely high dewpoints ranging from 75 to 80 to produce heat index readings above 110 in most locations, and localized readings up to around 120 were observed. Some areas saw relief from the heat on July 7th, especially portions of southern Illinois and southwest Indiana. Additional relief in the form of scattered showers and thunderstorms occurred on the 8th. Paducah's heat index of 114 on July 5 was their highest heat index since August 3, 2011. Paducah also managed to reach a peak heat index of 110 on 4 straight days from July 5-8. This was the first time Paducah observed 4 straight days exceeding a 110 degree heat index since July 31 - August 3, 1987. Triple digit temperatures were also experienced for some areas. In Evansville, this was the first time since 2012 that high temperatures reached 100 degrees. For Paducah, it was the first time since 2016 reaching 100.

Records and 100 Degree Temps
Heat Index Graphics
Upper Level Pattern

Records and Triple Digit Temperatures:

Record warm lows were established at all 5 climate sites on July 6th with lows remaining in the upper 70s to around 80 degrees. No record highs were set during this heat wave. However, several locations reached 100 degrees. In Evansville, it was the first time since 2012 that temperatures soared above 100. They also achieved a rare feat on July 6 when the high hit 100 and the low only fell to 80 degrees. The last time they observed a high over 100 and low remaining above 80 on the same day was way back on June 26, 1978. In Paducah we hit 100 degrees for the first time since June 2016.

Heat Index Graphics and Table:

Observed Heat Index Readings Monday July 4th through Friday July 8th, 2022 (Click images to enlarge)

The table below shows the maximum daily heat index readings observed at all airport locations (ASOS/AWOS) and Kentucky Mesonet stations across our 58 county forecast area. These are the most reliable and accurate stations across the region. The bottom row of the chart gives the highest daily heat index reading observed across the area from these 32 stations. The heat index is calculated from a combination of air temperatures and dewpoint temperatures or relative humidity.

Maximum Daily Heat Index Readings:

Location	Station Type	July 4	July 5	July 6	July 7	July 8
Cape Girardeau MO	ASOS	104	111	109	111	109
Carbondale IL	ASOS	106	113	111	108	106
Evansville IN	ASOS	101	109	107	90	102
Paducah KY	ASOS	104	114	111	112	110
Poplar Bluff MO	ASOS	105	114	111	114	111
Cairo IL	AWOS	105		115	107	106
Carmi IL	AWOS	107	121	113	106	108
Fairfield IL	AWOS	100	111	102	89	101
Fort Campbell KY	AWOS	111	109	107	109	109
Greenville KY	AWOS	103	109	110	112	110
Henderson KY	AWOS	105	114	110	99	108
Madisonville KY	AWOS	102	110	111	109	110
Marion IL	AWOS	108	117	114	109	108
Marion KY	AWOS	102	109	107	108	106
Mayfield KY	AWOS		109	109	109	109
Metropolis IL	AWOS	103	111	111	109	111
Murray KY	AWOS	105	112	112	109	111
Owensboro KY	AWOS	105	109	111	96	108
Perryville MO	AWOS	109	119	110	111	110
Sikeston MO	AWOS	103	113	110	109	113
Benton KY 4 N	KYMN	103	111	112	111	112
Cadiz KY 4 SW	KYMN	107	113	112	112	113
Calhoun KY 5 NW	KYMN	107	114	116	104	109
Elkton KY 5 SW	KYMN	115	119	119	122	118
Greenville KY 6 N	KYMN	105	113	114	115	115
Henderson KY 5 E	KYMN	107	115	114	95	106
Hickman KY 2 E	KYMN	104	112	109	113	112
Hopkinsville KY 6 N	KYMN	106	114	115	112	115
Madisonville KY 4 S	KYMN	107	115	117	113	115
Marion KY 4 NE	KYMN	105	115	116	114	109
Mayfield KY 6 SW	KYMN	108	116	114	115	115
Morganfield KY 4 E	KYMN	109	118	118	113	109
Murray KY 1 W	KYMN	104	111	112	109	114
Princeton KY 2 SE	KYMN	105	109	110	108	111
Daily Maximum:		115	121	119	122	118

Upper Level Pattern

The graphics below show observed 500 mb heights, wind, and temperature. This shows the overall weather pattern approximately 20,000 feet above the surface. The higher heights are indicative of upper level ridging which developed across the southern U.S. from July 4 through 8. Eventually the ridge gets squashed further south and west of our area as a cold front makes passage late on July 8th into early July 9th.


Valid 7 PM July 3, 2022	Valid 7 PM July 4, 2022

Valid 7 PM July 5, 2022	Valid 7 PM July 6, 2022

Valid 7 PM July 7, 2022

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