Tom - if you continue to see these and don’t get a good explanation, you might want to contact WF Support for a replacement hub or get them involved to dig much deeper…
You might check for duplicate packets. I can’t find specific mention of delayed observations in a quick check of the forums…
Here’s some links mentioning retransmit of data specifically…
From: https://community.tempest.earth/t/possible-duplicate-udp-packets/971
from @dsj (note - this is 2 years old): “The hub_status event is added to the event queue periodically. It could be that extra events got queued up while trying to reconnect to the mqtt server or some other thing was causing the wifi thread to be busy…”
Another one mentioning retransmits etc. that is open for all to read…details are in the discussion if you click the link for this one…
Another old one pre-prod days in a closed forum…
https://community.tempest.earth/t/release-candidate-hub-firmware-v91/1748/40
(from mid-2018) "The observation timestamps are generated by the HUB using the bootup timestamp from the AIR/SKY by applying an offset generated from the transmit-start packet.
…When the AIR/SKY transmits an observation it receives an ACK from the HUB indicating the observation has been received. If the AIR/SKY doesn’t get the ACK it’ll store the observation ring buffer. The device will then try to retransmit the observation during the next scheduled transmission window a minute later. The AIR/SKY will keep adding observations to the ring buffer and the oldest observations will drop off when the buffer is full.
Sometimes the AIR/SKY will transmit an observation and the HUB will receive it, but the AIR/SKY will miss the ACK from the HUB. This causes the AIR/SKY to re-transmit the same data again, even though the HUB already received the data. The HUB will usually filter out those duplicate observations, but there are instances where the HUB can’t do that. In that case we just re-transmit the data, which is where some of the duplicate observations come from.
That’s a pretty broad outline of the communication between the HUB and the weather devices. The whole communications stack is pretty complex"
It would be great if one-of-these-days we had a nice description of how the sensor and hub talk, and how the hub talks with the WF servers, just to capture things so we don’t need to speculate on pieces of the puzzle from years ago…