No spike, no sharp climb: the air just sits a bit above normal. Is that missed?
Los Angeles, 20 Aug: PM2.5 drifted to about twice its usual level with no sudden jump. A slow-drift detector catches it; the spell then lasts days without another message.
White line: PM2.5 each hour. Grey: what's usual here at that hour. Click any hour to see the watch when the agent decided about it.
Nothing to say Stayed quiet: nothing unusual for this hour.
Agent's note: Nothing unusual.
NO_TRIGGER · decided 7:20am about the 5am reading
08:00
Thu 20 Aug
All clear in Los Angeles
Watched 10 hours: nothing unusual for Los Angeles