Here you can view climatologies for a number of UK radiosonde sites, calculated using data provided by the University of Wyoming.
Despite applying some fairly extensive and rigorous automatic QC procedures, it is unlikely to be 100% perfect (some erroneous data slipping through, and some genuine data being filtered out), so you must use
your judgment especially when looking at specific extremes or absolute values.
The most recent ascent is shown on the plot, marked by a red X. You can see data for all the latest ascents by visiting the "Current Ascent Table" link at the top of the page