Export query to EXCEL in PHP error UTF-8

Question

When I export the data the UTF-8 is not acting, how can I solve this?

// Formatação do header do arquivo
header ("Expires: Mon, 18 Nov 1985 18:00:00 GMT");
header ("Last-Modified: ".gmdate("D,d M YH:i:s")." GMT");
header ("Cache-Control: no-cache, must-revalidate");
header ("Pragma: no-cache");
header ("Content-type: application/x-msexcel");
header ("Content-Disposition: attachment; filename=Dados.xls");

header ("Content-Type: text/html; charset=UTF-8");
echo "\xEF\xBB\xBF";

?>
<table>
    <thead>
        <tr>
            <th>Fazenda</th>
            <th>Talhão</th>
            <th>Data</th>
            <th>Deficit (mm)</th>
            <th>Irrigação (mm)</th>
            <th>Irrigação (h)</th>
            <th>Velocidade (%)</th>
            <th>Pluviometria (mm)</th>
            <th>Temp Min (°C)</th>
            <th>Temp Med (°C)</th>
            <th>Temp Max (°C)</th>

        </tr>
    </thead>

    <tbody>
        <?php
            while ($Dado = $conexao->busca($Dados))
            {
                ?>
                <tr>
                    <td><?=$Dado['Nome_Fazenda']?></td>
                    <td><?=$Dado['Nome_Parcela']?></td>
                    <td><?=$Dado['Data_Irr']?></td>
                    <td><?=$Dado['Deficit']?></td>
                    <td><?=$Dado['IrrMM']?></td>
                    <td><?=$Dado['IrrHS']?></td>
                    <td><?=$Dado['Velocidade']?></td>
                    <td><?=$Dado['Pluviometria']?></td>
                    <td><?=$Dado['Temp_Min']?></td>
                    <td><?=$Dado['Temp_Med']?></td>
                    <td><?=$Dado['Temp_Max']?></td>
                </tr>
                <?php
            }
        ?>
    </tbody>

Answer 1

The header()s should always come at the top of the page before anything:

<?php
    header ("Expires: Mon, 18 Nov 1985 18:00:00 GMT");
    header ("Last-Modified: ".gmdate("D,d M YH:i:s")." GMT");
    header ("Cache-Control: no-cache, must-revalidate");
    header ("Pragma: no-cache");
    header ("Content-type: application/x-msexcel");
    header ("Content-Disposition: attachment; filename=Dados.xls");
    header ("Content-Type: text/html; charset=UTF-8");