Rainbows

How come you can only get just one rainbow I know occasionaly you can get 2 but why not always

Secondary rainbows are caused by a double reflection of sunlight inside the raindrop. because of the second reflection, the colours of a secondary rainbow are inverted compared to the primary bow, with blue on the outside and red on the inside.

and sometimes it is not always reflected

hope I helped ... 3

yes it all depends on the intensity of the sunlight and the angle at which the sun is at, sunshowers can create the double rainbow, I swear I saw a triple rainbow once the third bow was very faint.

Occasionally, a second, dimmer, and thicker secondary rainbow is seen outside the primary bow. Secondary rainbows are caused by a double reflection of sunlight inside the raindrops, and appear at an angle of 50°–53°. As a result of the second reflection, the colours of a secondary rainbow are inverted compared to the primary bow, with blue on the outside and red on the inside. The dark area of unlit sky lying between the primary and secondary bows is called Alexander's band, after Alexander of Aphrodisias who first described it.