The Komorëbi column in the December 19th/26th issue of Jinja Shinpō is about the “Month with Kami” in Izumo. That is the tradition that all the kami of Japan gather in Izumo in the tenth month of the lunar calendar, which is accordingly called the “month without kami” (kan’nazuki) elsewhere.
The author is the chief priest of a jinja in the area, and this is one of the jinja that welcomes the visiting kami. He says that, this year, immediately after he had completed the ceremony to welcome the visiting kami by quietly closing the doors to the jinja where they would stay, a strong wind blew up, and rain started hammering on the ground. He also mentioned a time a few years earlier, when it had been raining before the matsuri, but had stopped just before they were due to start.
He comments that, although the kami and their travels cannot be seen directly, you can see their influence on the clouds.
This sort of story is not uncommon. A famous one comes from the last Shikinen Sengū at Jingū. Precisely at the moment that the kami was being transferred from the old sanctuary to the new one, a strong wind blew through the treetops, as if responding to the movement of the kami.
Now, these events might be due to the kami. They might also be due to the human tendency to remember things that are striking. I have read a lot of accounts of matsuri in Jinja Shinpō that say something like “unfortunately, it was raining all day”, so the kami do not always fix the weather. Still, the fact that the evidence is not decisive does not mean that the kami do not, at least sometimes, intervene with the weather or other situations surrounding matsuri.
That aspect aside, it is interesting that this sort of belief seems to be quite widespread in the Shinto community.