Zone 1AVery Hot (Zone 1)

Climate Zone 1A - Very Hot, Humid

Very hot summers with high humidity year-round. Minimal heating requirements. This climate zone encompasses parts of Florida, Hawaii, Louisiana, Texas and includes major cities like Miami, Key West, Honolulu, Brownsville.

Design Temperatures

Winter Design Temperatures

35°F to 50°F

Used for heating load calculations and equipment sizing

Summer Design Temperatures

95°F to 105°F

Used for cooling load calculations and equipment sizing

Heating & Cooling Degree Days

Heating Degree Days (HDD)

0 - 2,000

Base 65°F. Higher numbers indicate more heating requirements and longer heating seasons.

Cooling Degree Days (CDD)

3,500 - 5,000

Base 65°F. Higher numbers indicate more cooling requirements and longer cooling seasons.

HVAC System Considerations

Key Considerations

  • Year-round cooling priority
  • Dehumidification critical
  • Hurricane-resistant equipment
  • Salt air corrosion protection
  • Minimal heating capacity needed

Common Equipment

  • High-efficiency air conditioners
  • Heat pumps with enhanced dehumidification
  • Whole-house dehumidifiers
  • Variable refrigerant flow systems

Energy Code Requirements

Equipment Efficiency

  • SEER 14+ minimum for air conditioners
  • Enhanced moisture control
  • Duct sealing requirements
  • Fenestration U-factor limits

Insulation Requirements

Walls:R-13 to R-15
Ceiling:R-30 to R-38
Floor:R-13 (if applicable)

Major Cities in Zone 1A

States with Zone 1A Areas

Quick Reference

Zone:1A
Temperature:Very
Moisture:Moist (A)
States:4
Cities:4

Calculate Load

Use our load calculators with the design temperatures and requirements specific to Zone 1A.