Grid table and alignment of multicolumn header cells

[somelinguist]

Is it possible to align a multicolumn header cell in a grid table differently than its sub-columns? For example, I tried the following to no avail to center the Temperature cell while maintaining left alignment for min, mean, and max:

+:--------------------+:---------------------:+
| Location            | Temperature           |
|                     |                       |
|                     +-------+-------+-------+
|                     | min   | mean  | max   |
+:====================+:======+:======+:======+
| Antarctica          | -89.2 | N/A   | 19.8  |
+---------------------+-------+-------+-------+
| Earth               | -89.2 | 14    | 56.7  |
+---------------------+-------+-------+-------+

pandoc -f markdown+grid_tables gridtable.md -o gridtable.html

<table style="width:64%;">
<colgroup>
<col style="width: 30%" />
<col style="width: 11%" />
<col style="width: 11%" />
<col style="width: 11%" />
</colgroup>
<thead>
<tr>
<th rowspan="2" style="text-align: left;">Location</th>
<th colspan="3" style="text-align: left;">Temperature</th>
</tr>
<tr>
<th style="text-align: left;">min</th>
<th style="text-align: left;">mean</th>
<th style="text-align: left;">max</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left;">Antarctica</td>
<td style="text-align: left;">-89.2</td>
<td style="text-align: left;">N/A</td>
<td style="text-align: left;">19.8</td>
</tr>
<tr>
<td style="text-align: left;">Earth</td>
<td style="text-align: left;">-89.2</td>
<td style="text-align: left;">14</td>
<td style="text-align: left;">56.7</td>
</tr>
</tbody>
</table>

Note: I'm actually more interested in producing a PDF via latex, but it seems to be the same issue:

\begin{longtable}[]{@{}
  >{\raggedright\arraybackslash}p{(\linewidth - 6\tabcolsep) * \real{0.3056}}
  >{\raggedright\arraybackslash}p{(\linewidth - 6\tabcolsep) * \real{0.1111}}
  >{\raggedright\arraybackslash}p{(\linewidth - 6\tabcolsep) * \real{0.1111}}
  >{\raggedright\arraybackslash}p{(\linewidth - 6\tabcolsep) * \real{0.1111}}@{}}
\toprule\noalign{}
\multirow{2}{=}{\begin{minipage}[b]{\linewidth}\raggedright
Location
\end{minipage}} &
\multicolumn{3}{>{\raggedright\arraybackslash}p{(\linewidth - 6\tabcolsep) * \real{0.3333} + 4\tabcolsep}@{}}{%
\begin{minipage}[b]{\linewidth}\raggedright
Temperature
\end{minipage}} \\
& \begin{minipage}[b]{\linewidth}\raggedright
min
\end{minipage} & \begin{minipage}[b]{\linewidth}\raggedright
mean
\end{minipage} & \begin{minipage}[b]{\linewidth}\raggedright
max
\end{minipage} \\
\midrule\noalign{}
\endhead
\bottomrule\noalign{}
\endlastfoot
Antarctica & -89.2 & N/A & 19.8 \\
Earth & -89.2 & 14 & 56.7 \\
\end{longtable}

[jgm]

It might be a bug - @tarleb worked on the grid table parser and might know.

[tarleb]

This appears to be the issue described in #9085. I didn't yet get around to fixing that, sorry.