One mark per day: how warm it got outside, against what the house used with car charging taken out. The curve is lopsided, and the reason is that only one end of it is about temperature at all.
The right-hand climb is air conditioning, and it is large: days above 82°F average — kWh against — in mild weather. The house holds 68 to 73°F all year whatever happens outside, so that gap is the cost of holding it.
The left-hand climb is not heating. Heat and hot water here are gas, so they barely touch this axis. Nor is it a response to cold, and one comparison rules that out: February averaged 38.8 kWh on days below 45°F, at a mean of 36°F — while December averaged 51.0 kWh at a milder 38°F. Colder month, twelve fewer kilowatt-hours a day.
Sorted by month the excess decays — December +13.4, January +7.9, February +1.2, March +0.9 — which is a calendar, not a thermometer. Seasonal lighting fits the shape. Something else may too; this chart can say it is not the weather, and stops there.
Car charging is removed first because it has nothing to do with temperature and would otherwise be read as a cold-weather load: it runs about three times higher in January than in April, on driving and cold-battery losses. That limits this view to the — days since the wall connector was installed.
warmer inside than outcooler inside than out each mark is one day