Not sure if this is useful, but here is a bash function I found a while back that comes in handy for me from time to time. This is just a snippet I found. It could be improved upon in a few ways.

    function temp()
    {
    # Shell script to convert Fahrenheit to Celsius Temperature or Celsius 
    # to Fahrenheit Temperature
    # -------------------------------------------------------------------------
    # Copyright (c) 2005 nixCraft project <http://cyberciti.biz/fb/>
    # This script is licensed under GNU GPL version 2.0 or above
    # -------------------------------------------------------------------------
    # This script is part of nixCraft shell script collection (NSSC)
    # Visit http://bash.cyberciti.biz/ for more information.
    # -------------------------------------------------------------------------
    # Fahrenheit and Celsius Temperature Scales more info:
    # http://en.wikipedia.org/wiki/Temperature_conversion_formulas
    # --------------------------------------------------------------------
    echo "*** Converting between the different temperature scales ***"
    echo "1. Convert Celsius temperature into Fahrenheit"
    echo "2. Convert Fahrenheit temperatures into Celsius"
    echo -n "Select your choice (1-2) : "
    read choice
     
    if [ $choice -eq 1 ]
    then
     echo -n "Enter temperature (C) : "
     read tc
     # formula Tf=(9/5)*Tc+32
     tf=$(echo "scale=2;((9/5) * $tc) + 32" |bc)
     echo "$tc C = $tf F"
    elif [ $choice -eq 2 ]
    then
     echo -n "Enter temperature (F) : "
     read tf
     # formula Tc=(5/9)*(Tf-32) 
     tc=$(echo "scale=2;(5/9)*($tf-32)"|bc)
     echo "$tf = $tc"
    else
     echo "Please select 1 or 2 only"
     exit 1
    fi
    
    }

As the other poster mentioned, going to thousands of a °C implies precision that simply isn't there. The math conversion between °F and °C gives repeating decimals, so you were already rounding. The other poster was simply pointing out that your choice of rounding was implying precision that was unwarranted. Rounding to 56.7°C would have been plenty enough to make sense (reverses back to 134.06).

I tried finding information on the precision of the DV record and couldn't, but I personally doubt it was more that hundredths of a °F. I'd love for someone to provide data on the instruments used to record that record though, for my own edification.

I warn that the following comment may amplify confusion because I don't understand how to think about this topic.

The OP comment edit asking for an alternative got me going:

//Edit: thinking more about this, I would throw it back at you - what would you write for converting the Fahrenheit value to Celsius? It’s one thing to say I’m wrong, which is fine, but you offer no alternative.//

Translation manufactures a false precision, i.e.:

Units translation seems to be a slippery slope: to maintain accuracy in translation context imbues the data with precision that may not exist in the original samples.

134F -> 56.67C

So a report with a precision of +/– 0.5 becomes precision +/– 0.005 via translation.

This seems like a hazard to chain of custody in any translated reports.

As to how important this is, this is open to consideration.

Discounting the contrived precision in context converges uncertainty at the scale of the least precise unit:

56.67C rounded to 57C = 134.6F -> 135F -> 57.222C -> 57C

And when further reported... +/– 0.5

There seems to be no alternative to maintaining precision in context than to imbue the data with false precision; the precision is required to avoid creeping noise.

Consider additional pitfalls in report hygiene, such as idiomatically omitting the full precision in context for a measurement that falls on a unit interval. Consider 134.000F recorded as 134F, then decontextualized to +/– 0.5.

It seems any chain of custody includes an implicit hazard of well-meaning custodians.

When does engineering goe wonky merely by being translated?

This might seem obsessive, but being open-minded about what it means to "translate" leads to more questions:

Consider precision regarding inter-disciplinary transposition of data where the context shifts from a relatively narrow scope of scientific research, say collection of temperature trends from ice cores, that's translated into very broad scope state policy, say a schedule of global average temperature change. For example consider an emissions policy based on a target of +1.5C over a 50 year window. You never see this policy written in precision corresponding to the basis of data collected— e.g., written as 1.500C— even though the geological basis intervals range from order 1000–1000000 years.

To me a policy target of order 1.5C seems fishy based merely on the precision of its presentation in scientific context. Shouldn't it be order more like 1.5000C?

I'm curious about inherent distortions that may attend any analytic approach to policy as data are moved been domains of reference.

The OP question surprised me; it seems to be a true conundrum, beyond the reach of any simple "alternative" in context.

What would you do, store in Fahrenheit and convert one-way based on context?