Calculation of cooling degree days is currently one of the most commonly used methods in heating, ventilation and air conditioning (HVAC) industry to describe the effect of outside air temperature on building cooling energy consumption. This paper presents values of cooling degree days and hours that were calculated using data of outdoor air temperature, measured at meteorological station in Riga (Latvia) during the period of last 10 years. Seven base temperatures were used, i.e. from 19.0°C to 26.0°C with 1°C increment. Fluctuations in a number of cooling degree days were found by comparing them to the values calculated as cooling degree hours. Total cooling degree number was about 50% higher when using degree hour approach, providing more accurate data for future energy consumption estimations. Yearly cooling degree days are given in a tabular form. This data could further complement the local building norms and regulations regarding design of HVAC systems and energy efficiency, filling the gap of missing information for methodology of simplified energy calculations in buildings.