Free degree day data, powered by EnergyCAP

EnergyCAP is the expert-driven energy management software that centralizes your utility, commodity, meter, and sensor data into a single, trusted source of truth, eliminating spreadsheet chaos and giving your team instant clarity. Our platform turns raw data into weather-normalized, decision-ready insights that help you benchmark performance, uncover anomalies, and control utility costs.

Average daily temperature is the "middle value" between the daily high and the daily low.

Example: Daily high = 70. Daily low = 50. Average daily temperature = 60.

A degree day is a measure of relative heating and cooling energy required by buildings. It's calculated as the difference between the average daily temperature and the balance point temperature. When the average daily temperature is above the balance point, the result is cooling degree days; when below, the result is heating degree days.

Example 1: Average daily temperature = 80. Balance point = 60. Cooling degree days = 20 CDD.

Example 2: Average daily temperature = 45. Balance point = 60. Heating degree days = 15 HDD.

The balance point temperature is the average daily outside temperature at which a building theoretically maintains a comfortable indoor temperature without heating or cooling. WDD defaults to 60F because that is a better indicator of energy usage in modern buildings.

The cumulative degree day charts help you compare one year's weather to another as it relates to building energy usage. If 2020 had 4,000 cumulative HDD and 2019 had 3,000 cumulative HDD, you can conclude that 2020 weather was 33% colder and required about one-third more heating energy.

Weather data recording stations sometimes experience failures. When a single day is missing, Weather Data Depot estimates it from adjacent data. If more than seven days in a row are missing, the year may be excluded as unreliable.

Click a month name in the Degree Day Comparison report to open the daily detail view.

The location is the city and state, postal code, or station code of the regional weather data to display.

The base year is the baseline calendar year to use in weather comparisons.

The comparison year is the current calendar year to use in weather comparison.

Each station records a daily minimum, mean, and maximum for these measurements. Each monthly value in the report is the average of the daily values you select for that month.

Example: The July value of the Daily Maximum dew point report is the average of the 31 daily maximum dew points in July.

Relative humidity is the amount of water vapor in the air, expressed as a percentage of the most the air could hold at that temperature. Because warm air can hold more moisture, relative humidity usually reaches its daily minimum in the afternoon and its maximum around sunrise.

The dew point is the temperature to which air must be cooled to become saturated (100% relative humidity). Unlike relative humidity, it does not change as the air warms and cools, so it is a direct measure of how much moisture is in the air. Higher dew points mean more moisture for building cooling systems to remove.

The wet bulb temperature is the lowest temperature that can be reached by evaporating water into the air. It is a function of ambient air temperature and relative humidity.