Michael:
There are a few issues going on with your data (at least the 2 attachments). If the source of the data is WL's own DataDrop, I believe there are built in functions to retrieve such data. see "guide/UsingTheWolframDataDrop" in the WL documentation.
I believe there are some Unicode encoding issues going on with the Degree symbol. I get an inkling view of your workflow. Some automated data collection perhaps from IOT (manually?) uploaded to WL Data Drop. Either the upload to the Drop has some issues or the download (retrieval process) has some issues. You do state that you think the issue is with drop, but I am not sure if you mean upload or download.
I came up with the following:
ClearAll[clean];
clean[x_] :=
Module[{}, {If[Head[x[[1]]] == String,
DateObject[StringReplace[x[[1]], "+0" -> ""], TimeZone -> 0]],
If[Head[x[[2]]] == String,
ToExpression[
StringReplace[x[[2]], {"F" -> "", "\[Degree]" -> ""}]],
ToExpression[
StringReplace[
ToString[x[[2]]], {"F" -> "", "\[Degree]" -> ""}]]]}];
DateListPlot[
TimeSeries[
Map[Function[clean[#]],
Import["hw.tsv", "Data", HeaderLines -> 1] ]]]
DateListPlot[
TimeSeries[
Map[Function[clean[#]],
Import["basement.tsv", "Data",
HeaderLines -> 1] ]]]
Returns values and no errors in both files. You may try the other 5 (or is it 3 more) using or following the above code style.
To convert the timestamp into a DateObject remove the "+0" and the time is converted to local time zone, so we add or set the time zone to 0. The temperature data has "F" and "[Degree] symbol. The WL treats "[Degree]" in a special way. Please see degree Go to the Encodings section and select "More" a few times. The capital A hat that shows up in your files are a side effect of encoding issues and how the degree symbol is treated in WL and Unicode as well as many other systems. See more degree When left alone Import seems to have taken care of this "degree" issue. If you import the data as plaintext using "Text" option the CapAhat returns.
Slight change in the clean function can produce a dataset that is also compatible with TimeSeries and also good to upload back to Data Drop
cleanq[x_] :=
Module[{}, {If[Head[x[[1]]] == String,
DateObject[StringReplace[x[[1]], "+0" -> ""], TimeZone -> 0]],
If[Head[x[[2]]] == String,
Quantity[
ToExpression[
StringReplace[x[[2]], {"F" -> "", "\[Degree]" -> ""}]],
"Fahrenheit"],
Quantity[
ToExpression[
StringReplace[
ToString[x[[2]]], {"F" -> "", "\[Degree]" -> ""}]],
"Fahrenheit"]]}];