There are some sensor probes which include special protection against sunlight and bad environmental conditions. For instance, the temperature, humidity and pressure probe has a special filter which allows humidity measurement but offers protection against water.
However, a lot of sensor probes include just a standard protection. If the final application involves bad environmental conditions and a lot of sunlight hours, Libelium suggests the usage of a solar radiation shield.
In addition, refer to corresponding section for more information about sensor probes.