UK river level
This is the level of the Great Ouse at Hemingford, measured every fifteen minutes and charted every six hours. Nobody set a target for a river. The lines on this chart come from the river's own behaviour over a dry stretch — so when rain arrives, the chart says so while the level is still perfectly ordinary. An alarm threshold tells you you are already in trouble. This tells you you are heading there.
River level at Hemingford — individuals & moving range
No points to chart yet
This feed is connected but has not collected a full sampling period yet. The chart appears as soon as the first complete points land.
What just happened
Written out in full, the moment the chart sees it. No statistics knowledge required.
Tick a rule off and its points, its shaded runs and its card below the chart go with it — nothing is refetched, so you are looking at the same readings judged by fewer rules. Change how often a reading is taken and watch the limits move. Sample too often and every reading is almost a copy of the one before it — the chart then thinks the process is far steadier than it is, and draws limits so tight that normal variation looks like a crisis. Only the setting marked (the real one) shows the limits that were locked at baseline and have never been recalculated since.
Data source: Environment Agency. This uses Environment Agency flood and river level data from the real-time data API (Beta), licensed under the Open Government Licence v3.0. SPC Visuals is not affiliated with Environment Agency.
Use this chart
https://www.spcvisuals.com/live/river-level
<iframe src="https://www.spcvisuals.com/live/river-level/embed" width="100%" height="440" style="border:0" title="UK river level — live control chart"></iframe>
Free to embed, no attribution required beyond the source's own (below). The embed carries a small credit link back here.
I-MR control chart of UK river level, drawn from Environment Agency. Limits were computed once from the first 32 points and frozen; they are never recalculated from the visible window. How these charts are built →
https://www.spcvisuals.com/live/river-level/card.png
Your data does this too
Connect a historian, a CSV, or an API. Same charts, same frozen limits, your process.