Heat Wave Expands From Out Of Texas To Mississippi Valley And Southeast

A dangerous heat wave that could top daily records has spread across the South, as well as northward into parts of the Midwest, but there is some relief on the horizon.

(CURRENT MAPS: Temperature | Heat Index)

H​ere's a look at the current situation and the forecast.

W​here heat alerts are in effect: The map below shows where excessive heat watches, warnings and advisories issued by the National Weather Service are in effect.

T​hese heat alerts are issued when the combination of heat and humidity pose a danger of heat exhaustion or heat stroke to those outdoors for prolonged periods of time or those without access to air conditioning.

Take this dangerous heat seriously. Avoid any prolonged, unnecessary outdoor activity, especially in the hottest part of the day. Check on the elderly and anyone else who may be living without air conditioning.

(​MORE: What Is A Heat Index?)

Here's what to expect: On Friday, hotter than average temperatures are forecast from the mid-Mississippi and lower Ohio valleys southward to the northern Gulf Coast. Daily record highs are possible in a few spots like Memphis, Tennessee, and Shreveport, Louisiana.

T​he core of the worst heat on Saturday will be in the South, from Georgia and northern Florida to the lower Mississippi Valley. Montgomery, Alabama, and Baton Rouge, Louisiana, could flirt with daily record highs.

T​emperatures from Sunday to Monday will begin to edge down in some areas of the South. That said, it will still be hot and humid like you would expect in this region during July.

The Texas heat wave set all-time records. This heat wave first hit Texas before expanding across the rest of the South.

It rewrote the history books for all-time record heat in a few locations across the Lone Star State where weather observations have been taken for over 100 years. Here's a recap.

-​ San Angelo, Texas, first tied their all-time record on June 19 (111 degrees), then smashed it a day later, reaching 114. They tied their new all-time record of 114 degrees again on June 21 and followed up with 112-degree highs both Sunday and Monday.

-​ Laredo, Texas, topped out at 115 degrees on June 19, which tied their all-time record from three other years.

I​t reached 119 degrees this past Friday at Rio Grande Village in Big Bend National Park. That was not only the nation's hottest temperature so far this year, according to weather historian Christopher Burt, but just missed the state's all-time record of 120.

A​nd while an unofficial record, a heat index of 125 degrees on June 19 was thought to be the highest heat index on record for Corpus Christi International Airport, according to the National Weather Service.

All-time records were also set in parts of Mexico last week, including in the town of Monclova in Coahuila state, as well as in Chihuahua state, according to world temperature records expert Maximiliano Herrera.

A​ccording to an analysis by Climate Central, climate change has made record heat in this Mexico-Texas heat wave at least five times more likely.

M​ORE ON WEATHER.COM:

A​merica's Top Weather Killer Is Heat

H​ere Are Three Signs Of Heat Exhaustion

H​ow To Cool Off Quickly In Dangerous Heat

F​ive Tips To Save Energy During A Heat Wave

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