A luminous electronic clock includes a multi-diameter forward tapered case frame; a transparent plate installed in a front circumferential edge of the case frame with a sealing ring mounted between them; a dial spaced behind the transparent plate and having time markers, temperature numbers and humidity numbers provided thereon; clock, thermometer and hygrometer movements mounted on a back side of the dial; hands of the clock and pointers of the thermometer and the hygrometer mounted on movement shafts and located on a front side of the dial; a set of LED lights installed around the clock movement shaft and located behind the dial; battery holders mounted behind the dial; and a case back fixedly held to a rear circumferential edge of the case frame by retaining springs and having windows corresponding to the movements and the battery holders.