Texas Heat Wave Has Smashed Some All-Time Records, And Will Expand Into Next Week

A​ Texas heat wave has already smashed all-time record highs in a few locations and shows no sign of letting up. The heat dome will also expand this weekend into next week.

T​his spell of dangerous, searing heat began building northward out of Mexico last week, and shifted into a higher gear earlier this week.

(CURRENT MAPS: Temperature | Heat Index)

Here are the all-time records that have been tied or set, so far. This heat wave isn't simply topping records for a given calendar day, but it has rewritten the history books for all-time record heat in some locations where weather observations have been taken for over 100 years.

-​ Del Rio, Texas, soared to 115 degrees on Wednesday, topping their previous all-time record set on Tuesday of 113 degrees.

-​ San Angelo, Texas, first tied their all-time record Monday (111 degrees), then smashed it on Tuesday, reaching 114. They tied their new all-time record of 114 degrees again on Wednesday.

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

I​t reached 119 degrees 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.

E​ach of these cities were as hot or hotter than Death Valley, California, had managed to tally through June 20. America's extreme heat champion has reached 113 degrees so far this season.

A​nd while an unofficial record, a heat index of 125 degrees Monday 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 in recent days, including in the town of Monclova in Coahuila state, as well as in Chihuahua state, according to world temperature records expert Maximiliano Herrera.

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.

(​MORE: What Is A Heat Index?)

The heat dome, or upper-level ridge of high pressure, will expand into parts of the Southwest and lower Mississippi valley, as well as a bit farther north in the Southern Plains. Highs in the mid- to upper 90s to low 100s will stretch from southern Arizona into New Mexico into Louisiana, Mississippi, Arkansas, Oklahoma and Kansas.

The extreme heat could last into early July. Significant heat relief is usually hard to come by in the Southern Plains from this point on in summer, unless a tropical system brings soaking rainfall.

The latest long-range outlook from NOAA suggests the heat is expected to linger over the Southern Plains, from New Mexico into Texas, Louisiana, Arkansas and Oklahoma, into early July – possibly including the July Fourth holiday.

Here is what's causing the extreme heat: A dome of high pressure aloft that's persisted much of this month over Mexico has bulged northward into the Southern Plains, spreading its extreme heat.

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.

S​o, take this dangerous heat seriously if you live in the Southern Plains. 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.

M​ORE ON WEATHER.COM:

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H​ere Are Three Signs Of Heat Exhaustion

H​ow To Cool Off Quickly In Dangerous Heat

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Jonathan Erdman is a senior meteorologist at weather.com and has been an incurable weather geek since a tornado narrowly missed his childhood home in Wisconsin at age 7. Follow him on Twitter and Facebook.

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