One of the great challenges in folklore is determining whether similarities are historically related or whether they are coincidental. /r/AskHistorians has repeated questions about why various cultures have flood stories - with the implication that there is some folk memory of the "Great Flood." Certain things are simply common to the human experience, and people being people, they often arrive at similar conclusions. People endure floods, so people tell stories about floods. The stories are not necessarily related and they certainly don't imply a single, huge, primal event.

Similarly, people have consistently viewed the event of the sun shining during a rain shower as remarkable. It is a twist of nature, and for many cultures, this begged the participation of the trickster of the indigenous folklore. Aside from it being a wiki site and therefore questionable, this inventory is useful to show the wide variety of possible explanations for the phenomenon. Many if not most cultures look to the trickster for an explanation (although not all involve this character). Many English-speaking cultures, for example, involve the devil, who often plays the role of a trickster.

It might be more appropriate to ask why foxes, jackals, and wolves are often cast in the role of a trickster. The cultures that place these animals in the role of being related to a sun shower are not necessarily drawing on a single, related tradition. Instead, many of them are independently drawing on the same conclusion; namely, that the event is related to the activity of a trickster, and the trickster is embodied by one of these creatures.

In short, the question, "Where did this piece of folklore originate?" implies that there is a single "ur" point for all these traditions. That is certainly not the case. Instead, we need to ask why cultures look to similar animals as their symbol for a trickster, and why a trickster is often associated with a sun shower.