Oklahoma City Climate Zone & Energy Code

Climate Zone: IECC Climate Zone 3A (mixed-humid). Oklahoma City has extreme climate variability — hot, humid summers (99°F/74°F cooling design) and genuine cold winters (13°F heating design) with frequent severe weather events.

Energy Code & Manual J Requirement: Oklahoma Residential Energy Code (IECC 2018, with some jurisdictions on newer editions). ACCA Manual J required for Oklahoma County and OKC metro HVAC permit applications.

Local Electric Utility: OG&E (Oklahoma Gas & Electric)

Building Department: City of Oklahoma City Building Department

Local Trade Association: ACCA Oklahoma / ASHRAE Oklahoma Chapter / SMACNA Oklahoma