Covering structure for external environments, said covering structure is provided with a device for regulating the sunlight penetration into the same external environments, adapted to be placed onto terraces, gardens, green spaces or paved areas or the like, such as to create a shady area, or by regulating the sunlight penetration into the same area, and by protecting this latter from bad weather such rain, snow, hail, ice and the like, said covering structure further comprises a peripheral frame with quadrangular shape or other suitable shape, arranged preferably horizontally, and supported at its vertices by at least four columns and provided into its interior with a free area, in which a set of adjustable vanes is inserted and fixed by hollow bodies of the frame, which vanes are arranged parallel and equally spaced away from each other, both longitudinally and transversally to the frame, depending on the needs of the user with the possibility to rotate around its own transversal axis, wherein heating means, connected to external power supplies, are applied to the frame and to the vanes, and are adapted to heat these latter for melting in a short time any possible deposit of snow, hail, ice or the like, said adjustable vanes in the closed position thereof forming a lower rectilinear surface and an upper undulated surface, characterized in that the adjustable vanes are each constituted by a section bar made of metal or other suitable stiff material and composed by two shells (54 and 55) joined to each other, of which the first lower shell is shaped with a horizontal flat face the end portions (57 and 58) of which are curved upward, the first end portion finishing with an overturned T-shaped groove for the entire width thereof, and adapted to house a gasket, the second end portion being connected with the lower part of the other shell, which in turn is shaped with a curvilinear face, convex upward, with the two end portions (62 and 63) thereof turned downward, the first end portion of which is joined to the upper part of the face in the part in which there is provided the end portion, thereby creating a small channel for the entire width of the vane, whereas the second end portion of which is free at its end portion, and two joining vertical walls (64 and 65) being provided spaced away to each other and interposed between the two shells (54 and 55), thereby creating a central hollow area, and two side hollow chambers (67 and 68), the first chamber of which being placed near the first end portion and the second chamber of which being placed near the second end portion, into the first chamber there being provided a cavity, adjacent and parallel to the vertical wall, into which a lengthened metallic body is integrally inserted, which is projected outward with a cylinder shaped portion, whereas into the central cavity, in the lower and upper part of its entire length, there are provided at least a pair of curved wings (72 and 73), which are spaced away and arranged symmetrical to each other with their concave profile, the so constituted adjustable vanes being arranged into the frame, with their own cylinder shaped portions freely inserted into the hollow bodies of the frame, in such a way that the vanes are arranged in the horizontal position, in which they are arranged one in contact with the other, in such a way that the gasket of a first vane abuts the lower part of the second end portion of a second vane adjacent to such end portion, and that the second end portion of the first vane abuts with its lower portion the gasket of a third vane adjacent to such end portion, in such a way that a uniform, and sealed covering is formed.