Heat Risk
Heat risk measures livability pressure, cooling cost exposure, and how recurring extreme temperatures affect day-to-day ownership.
~1,300+
Heat deaths per year (US)
~4,000 CDD
Phoenix avg cooling days/yr
30–50% higher
HVAC cost premium in extreme heat
About heat risk
Extreme heat is the deadliest weather hazard in the United States, killing more Americans per year than hurricanes, tornadoes, and floods combined. It is also the hazard with the highest signal-to-noise ratio in property valuation: the same property in Phoenix, AZ and Buffalo, NY has materially different annual cooling costs, HVAC replacement cycles, and roof wear patterns, but the difference often does not show up in the listing price until the buyer's first summer utility bill.
NOAA's climate normals — the 30-year average daily highs, lows, and cooling degree days — are the most reliable federal signal. The Risk Before Buy heat score uses NOAA county-level data to rank a city against the national distribution. Local utility rates, attic insulation, and HVAC efficiency create the property-level variation; the snapshot tool does not surface these, so buyers in high-heat markets should plan an HVAC inspection and a utility-cost review before closing.
Heat risk is also the hazard most reshaped by climate change. The number of days per year above 95°F has been rising across most of the southern tier of the United States, and the trend is expected to continue. A property that is in a 'Moderate' heat band today may be in a 'High' or 'Extreme' band within 10 to 20 years. The 30-year projection in the full Risk Before Buy report quantifies this.
What signals a heat-exposed parcel
NOAA's cooling degree days (CDD) are the most reliable national signal. Markets with 3,000+ CDD/year are in the high-heat band; markets with 4,000+ CDD/year are in the extreme band (Phoenix, Tucson, Las Vegas, parts of inland California and South Texas). Parcel-level signals include HVAC age (units over 10 years old are typically nearing end-of-life), attic insulation R-value, and roof material (light-colored or reflective roofs reduce heat load).
Risk Bands Explained
Extreme heat zone (95°F+ days)
100+ days/year above 95°F — significant cooling cost and health burden
High heat zone
Elevated cooling loads and heat stress days — HVAC sizing critical
Moderate heat zone
Below-national-average extreme heat days
Buyer Action Checklist
- 01
Verify HVAC sizing, age, and efficiency rating for the local heat load
- 02
Check attic insulation and roof material — dark roofs dramatically increase cooling loads
- 03
Research utility rates in the area — some heat markets have peak pricing that inflates summer bills
- 04
Factor air quality into heat analysis — extreme heat and poor AQI often co-occur in the Southwest
Data source: NOAA · NOAA Climate data
Check heat risk for a specific address
Free snapshot available for any US address — no account required.
Heat Risk FAQ
Is extreme heat covered by homeowners insurance?
Heat-related damage to HVAC systems is generally covered under standard homeowners policies, but subject to the deductible and the policy's equipment breakdown limits. Heat-driven foundation issues (in some soils) and roof material degradation are typically not covered. A separate home warranty can cover HVAC replacement costs that exceed the policy deductible.
How is the heat score different from cooling degree days (CDD)?
Cooling degree days are the NOAA-published, county-level measurement of annual cooling demand. The Risk Before Buy heat score is a national percentile derived from CDD plus several supplementary NOAA climate signals. CDD is the dominant input; the score is the cross-market comparison metric.
How is extreme heat expected to change?
The number of days per year above 95°F is rising across most of the southern tier of the US, and the trend is expected to continue. A property that is in a 'Moderate' heat band today may be in 'High' or 'Extreme' within 10 to 20 years. The 30-year projection in the full report quantifies the trajectory.