Random weather plugin changed weather, temperature, etc. before DX 11 update, but somehow it did not work due to weather setting of rF2. As far as I have confirmed, setting the weather to Clear means that it will not rain regardless of the plugin's output. In other settings I think it will probably rain.
Also, the default setting of the plugin sets the rain chance to 30%, but it seems to be too high. Since there is opinion that around 5 to 7 is appropriate, please adjust each until the next update.
After plugin header for DX11 is released, I will update this plugin after a long time.