During winter, the roof collects snow, hence the name Yukimi-dōrō 「雪見燈籠」 which can be translated as "snow viewing lantern".
I photographed this lantern during summer, in the garden of the Hasedera Temple from Kamakura.
EXIF info:
Nikon D90
Lens: VR 18-55mm F/3.5-5.6G
Focal Length: 18mm
Aperture: F/5.6
Shutter Speed: 1/500s
ISO Sensitivity: ISO 400