Charging systems for wearable UV sensing devices. The charging systems include a wearable housing including a UV sensor, a central conductor, and at least one annular conductor extending around the central conductor. The system also includes a charger that has at least first and second conductive contacts, where the first and second contacts are spaced from each other and the central conductor and annular conductor are spaced from each other such that the first and second contacts are aligned with the central conductor and the annular conductor, respectively, when the housing and charger interface.