Dew Point Calculator — A Dew Point Series From Your Own Data
A dew point from one pair of readings is a spreadsheet formula. A dew point from a whole record tells you something a single pair cannot: how close the air came to saturating, and when it got there. Drop in a logger export and get the dew point over time, the depression between it and the air, and every condensing spell marked — computed by inverting FAO-56 Equation 11 exactly, with the equation on the figure.
Your data
Drop a logger CSV here
HOBOware and Postlad exports are recognised automatically. It is read on this machine — nothing is uploaded.
Synthetic four-day open-field record at half-hourly intervals, as plain CSV with ISO timestamps declaring +02:00. It was generated from a drifting dew point with a diurnal temperature cycle over it, so three of the four nights cool all the way to saturation and one — the night the front passes — does not. Not measured data.
SVG is vector — scale it to any size in Illustrator, Inkscape or LaTeX without losing quality, and edit the type. Use it unless a journal insists on raster.
Options
Series
In °C. This tool never converts units.
In percent, 0–100.
Figure
Condensation
A tolerance for sensor error near saturation, not a physical constant. Set it to 0 for the strict definition.
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.