Dew, frost, and soiling on the optical dome of a radiometer all have a significant negative impact as obstructions can lead to bad readings. Ventilation and heating are two ways to deal with this problem.

Weather conditions have a huge influence on photovoltaic output. Even intermittent cloud cover can have a dramatic effect on incident solar energy, while other factors like air temperature, wind direction and speed, precipitation, humidity, and air pressure can all influence the efficiency of solar cells. Monitoring weather conditions accurately is crucial to understand variations in PV plant performance.