What the weather costs to keep a home comfortable in every county: the air-conditioning bill and the heating bill, paid in whatever fuel each neighborhood actually uses, at today's prices. Then, who can afford it: how many households spend more than 6% of their income just on heating and cooling.
How much energy. The Energy Department's 2020 Residential Energy Consumption Survey metered the heating and cooling use of 18,496 homes, each with its own heating and cooling degree days. From it: how much electricity air conditioning uses per cooling degree day, and how much gas, propane, heating oil or electricity heating uses per heating degree day, by region, adjusted for each state's air-conditioner ownership. It's also adjusted for each neighborhood's mix of detached houses, townhouses, apartments and mobile homes, because an apartment uses about a quarter of a detached house's heat.
How much weather. Each county's cooling and heating degree days (base 65 °F) from NOAA's nClimGrid: the 1996–2025 normal, or the last 12 months.
What it costs. Each state's current residential prices from the EIA: electricity (average of the last 12 months), natural gas (latest year), and propane and heating oil (last winter's weekly survey, or the state annual price where the weekly survey doesn't cover it).
Who can pay. Each census tract's household-income distribution (ACS 2020–2024). A household counts as "over 6%" when this heating-and-cooling bill tops 6% of its income, a common energy-affordability line, and the full energy bill runs higher still. Water heating, lights and appliances aren't weather-driven and aren't counted. Neither are homes heated with wood, or not heated at all (about 4%).
These are modeled bills for a typical home in each neighborhood, not anyone's actual statement. The model tracks what RECS households reported by state (correlation 0.93 for cooling, 0.90 for heating); it runs higher than 2020 because prices have risen since then.