To obtain the suitable hourly methods for key energy-saving meteorological parameters under maritime climate condition, this study analyzed five energy-saving meteorological parameters including temperature, dew point temperature, relative humidity, wind speed, and atmospheric pressure. By comparing representative inland and coastal cities, the applicability and characteristics of linear interpolation, cubic spline interpolation, piecewise cubic Hermite interpolation, Akima interpolation, and radial basis function interpolation in maritime climate conditions were discussed. Results show that under maritime climate conditions, the best interpolation method for winter temperature was cubic spline interpolation, and that for humidity was Akima interpolation; the best interpolation method for summer temperature and humidity was piecewise cubic Hermite interpolation. The best interpolation method for dew point temperature was linear interpolation in both winter and summer, and that for wind speed and atmospheric pressure was Akima interpolation in both winter and summer. The interpolation accuracy of different meteorological parameters had the same overall trend in the same season. The interpolation accuracy in summer from small to large was wind speed, dew point temperature, humidity, temperature, and atmospheric pressure, and that in winter was dew point temperature, wind speed, humidity, temperature, and atmospheric pressure. The interpolation accuracy of dew point temperature, humidity, and wind speed was greatly affected by the region, and they were affected in an ascending order of humidity, dew point temperature, and wind speed. The interpolation accuracy of temperature and atmospheric pressure data was less affected by the region.