The CSO hygrometer and thermometer are mounted inside the dome. So if the shutter is closed, the temperature is usually higher and the relative humidity lower than outside.
Hawaii Upper Air Forecast (NOAA Environmental Modeling Center; 12 km resolution, 84 hours).
The “700 mb Height and RH” images, showing the height (in meters) of the 700 mb surface and the relative humidity at that level, are probably of most interest in predicting the summit weather.