El Nino Watch
Data older than it should be for that source. Stale values are marked with a clock sign; a stale "all calm" is treated as unknown.
Koh Samui watch
Each source has a maximum age that matches how often it really updates: a few hours for weather forecasts, a day or two for satellite products, about two months for a monthly index.
When the newest data is older than that, it is stale. The value is still shown (with its date and a warning), because it can still be useful context. But for the Samui risk level, a stale factor that would read 0 becomes unknown, and a stale critical factor makes the overall level Unknown.
Look for the "stale" chip and the "as of" date next to every value.