一、接口申请
通过聚合https://www.juhe.cn/docs/api/id/39自助申请开通接口权限。

二、通过PHP发起城市天气查询

// 请求的接口URL
$apiUrl = 'Http://v.juhe.cn/weather/index';
// 请求参数
$params = [
    'cityname' => '北京', // 要查询的城市
    'fORMat' => '2',
    'key' => 'xxxxxx' // 您申请到的接口请求key
];
$paramsString = http_build_query($params);

// 发起接口网络请求
$response = juheHttpRequest($apiUrl, $paramsString);
$result = JSON_decode($response, true);
if ($result) {
    $errorCode = $result['error_code'];
    if ($errorCode == 0) {
        // 获取返回的天气相关信息，具体根据业务实际逻辑调整修改
        $data = $result['result'];

        // 打印当前实况天气信息,更多字段请参考官方接口文档
        echo "当前城市：{$data["today"]["city"]}".php_EOL;
        echo "当前温度：{$data["sk"]["temp"]}".PHP_EOL;
        echo "当前湿度：{$data["sk"]["humidity"]}".PHP_EOL;
        echo "当前天气：{$data["today"]["weather"]}".PHP_EOL;
        echo "当前风向：{$data["sk"]["wind_direction"]}".PHP_EOL;
        echo "当前风力：{$data["sk"]["wind_strength"]}".PHP_EOL;

    } else {
        // 请求异常
        echo "请求异常:{$errorCode}_{$result["reason"]}".PHP_EOL;
    }
} else {
    // 可能网络异常等问题，无法正常获得相应内容，业务逻辑可自行修改
    echo "请求异常".PHP_EOL;
}

function juheHttpRequest($url, $params = false, $ispost = 0)
{
    $httpInfo = array();
    $ch = curl_init();

    curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
    curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (windows NT 10.0; WOW64) AppleWEBKit/537.36 (Khtml, like Gecko) Chrome/41.0.2272.118 Safari/537.36');
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 3);
    curl_setopt($ch, CURLOPT_TIMEOUT, 12);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    if ($ispost) {
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $params);
        curl_setopt($ch, CURLOPT_URL, $url);
    } else {
        if ($params) {
            curl_setopt($ch, CURLOPT_URL, $url.'?'.$params);
        } else {
            curl_setopt($ch, CURLOPT_URL, $url);
        }
    }
    $response = curl_exec($ch);
    if ($response === FALSE) {
        // echo "cURL Error: ".curl_error($ch);
        return false;
    }
    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    $httpInfo = array_merge($httpInfo, curl_getinfo($ch));
    curl_close($ch);
    return $response;
}