"Case 00359522: AcuRite Rain Tube
Good Morning,
Thank you for your email regarding your AcuRite Rain Tube. Unfortunately, the unit can become discolored or "cloudy" over time if it is exposed to a lot of direct sunlight. If your unit was purchased within the last year, we would be happy to send a replacement under warranty. We would ask only that you send a copy of your receipt, along with your mailing address.
Once the unit is discolored, there is no recommended way to clean or restore the original appearance."