For example: Today, a balmy 17 degrees in Dunedin and beautifully sunny all day. Packet loss and jitter begins to increase at about 9am and peaks about 1pm with 60% loss, then at 2pm as if flicking a switch it returns to nearly 0% loss. From looking at the graphs over time, this does happen quite often but not every day and the loss today is definitely the worst I've seen it (but also the warmest/sunniest day we've had in Dunedin for quite a while).
How hot is the equipment concerned? We had some degraded thruput issues once which were (after some time) determined to be directly related to the temperature inside the local LAN distribution cabinet. Improved A/C helped. If your RX gear (beyond the Dish) is getting warm, thats a thought. Beyond that, usually Sunlight / good weather conditions are better for Radio, especially VHF+ frequencies. Rain fade, etc, is definately more likely than Sun fade (!) IMHO Mark.