Threshold and Exceedance Analysis — Hours Past a Limit, Counted Honestly
ProSet a threshold and a direction and get the answer three ways: every exceedance event with its start, end, duration and peak; the hours past the line in each day, month or season; and the longest run. Time the logger did not record is reported separately as unknown, because it is not time below the limit — and an event still under way when the record ends is reported as ongoing rather than quietly closed at the last row.
Your data
This tool is showing its sample dataset.
Everything in the figure is real output computed in your browser. Loading a file of your own is part of Pro.
Synthetic hourly air and soil temperature, 5 to 16 April 2026, built around four frosts: one already under way when the record starts, one clean night, one interrupted by a three-hour logger outage, and one still under way when the record ends. Not measured data.
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Options
Threshold
The threshold is compared in the file’s own units. Nothing is converted.
A preset fixes the threshold and the direction. Only the frost one is a physical constant; the others are conventions.
Periods
Days and months are read in the file’s declared offset. Seasons are the meteorological ones.
Events
Readings. The default of 1 drops nothing — one reading past a threshold is still an observation.
Whether a frost that paused for twenty minutes is one event or two. Merging never bridges a stretch with no readings in it.
Figure
All of that was worked out in this browser tab. Your file was not uploaded, and no request goes out while you work — open the network panel and watch, if you like.
The figure above is this tool's sample dataset, and everything in it is real output — every option works and every number is computed here in your browser. Running Threshold & exceedance on a file of your own is part of Pro.