Heat Advisory and Extreme Heat Warning Issued for Eight Oklahoma Counties
The National Weather Service has issued heat alerts with heat index values reaching up to 109 across central and southern Oklahoma.
3 reports on this incident · first at Aug 19, 2026, 1:56 p.m. ET
Earlier reports
Aug 19, 2026, 2:26 p.m. ET
Heat Advisory Thursday for Grady, McClain, Cleveland and Five More Oklahoma Counties
Hot temperatures and high humidity may cause heat illnesses across eight central and southern Oklahoma counties on Thursday, Aug. 20, 2026, according to the Heat Advisory product issued by National Weather Service Norman OK. The advisory record states that heat related illnesses increase significantly during extreme heat and high humidity events.
The advisory takes effect at 1 PM CDT Thursday and runs to 8 PM CDT the same evening. The alert was issued at 12:28 PM CDT on Aug. 19, 2026, and its official headline reads: "HEAT ADVISORY IN EFFECT FROM 1 PM TO 8 PM CDT THURSDAY."
For the Heat Advisory, the record gives heat index values up to 108. For the Extreme Heat Warning, it describes dangerously hot conditions with heat index values up to 109, in effect until 8 PM CDT that evening. The product covers 24 zones.
The counties named in the record are Cleveland, Grady, McClain, Pottawatomie, Seminole, Hughes, Jefferson and Stephens. Communities listed include Purcell, Ryan, Duncan, Tuttle, Chickasha, Seminole, Holdenville, Wewoka, Waurika, Blanchard, Shawnee, Wetumka, Newcastle, Ringling, Norman and Moore.
The National Weather Service advises residents to drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.
The alert is classified at the advisory level in the National Weather Service record.
Aug 19, 2026, 1:56 p.m. ETFirst report
Heat Advisory in Effect for Grady, McClain and Cleveland Counties From 1 PM to 8 PM CDT Thursday
An official alert record issued by National Weather Service Norman OK places a Heat Advisory in effect on August 20, 2026, beginning at 1 PM CDT and expiring at 8 PM CDT. The record was issued at 12:28 PM CDT on August 19, 2026, and carries the headline "HEAT ADVISORY IN EFFECT FROM 1 PM TO 8 PM CDT THURSDAY."
According to that record, heat index values up to 108 are expected under the Heat Advisory. The same record describes dangerously hot conditions with heat index values up to 109 under an Extreme Heat Warning, which runs until 8 PM CDT this evening.
The alert covers 24 zones across Cleveland, Grady, McClain, Pottawatomie, Seminole, Hughes, Jefferson, and Stephens Counties. Affected cities listed in the record include Purcell, Ryan, Duncan, Tuttle, Chickasha, Seminole, Holdenville, Wewoka, Waurika, Blanchard, Shawnee, Wetumka, Newcastle, Ringling, Norman, and Moore.
The record states that hot temperatures and high humidity may cause heat illnesses, and that heat related illnesses increase significantly during extreme heat and high humidity events.
The issuing office advises people to drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.
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Revision history
- Version 119 Aug 2026, 18:26current
First published.
- Version 119 Aug 2026, 17:56current
First published.
- Version 119 Aug 2026, 18:39current
First published.
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