// Example Wunderground API test code for C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net;
using System.Xml;
using System.IO;

namespace Wunderground_API_Test
{
    class Program
    {
        static void Main(string[] args)
        {
            //Start program
            Console.WriteLine("Starting Weather Undeground Web API Test...");
            string wunderground_key = "XXXXXXXXXXXXXX"; // You'll need to goto http://www.wunderground.com/weather/api/, and get a key to use the API.

            parse("http://api.wunderground.com/api/"; + wunderground_key + "/conditions/q/UK/Cheltenham.xml");


            // End.
            Console.WriteLine("Press any key to exit.");
            Console.ReadKey();
        }

        //Takes a url request to wunderground, parses it, and displays the data.
        private static void parse(string input_xml)
        {
            //Variables
            string place = "";
            string obs_time = "";
            string weather1 = "";
            string temperature_string = "";
            string relative_humidity = "";
            string wind_string = "";
            string pressure_mb = "";
            string dewpoint_string = "";
            string visibility_km = "";
            string latitude = "";
            string longitude = "";
            string feelslike = "";

            var cli = new WebClient();
            string weather = cli.DownloadString(input_xml);

            using (XmlReader reader = XmlReader.Create(new StringReader(weather)))
            {
                // Parse the file and display each of the nodes.
                while (reader.Read())
                {
                    switch (reader.NodeType)
                    {
                        case XmlNodeType.Element:
                            if (reader.Name.Equals("full"))
                            {
                                reader.Read();
                                place = reader.Value;
                            }
                            else if (reader.Name.Equals("observation_time"))
                            {
                                reader.Read();
                                obs_time = reader.Value;
                            }
                            else if (reader.Name.Equals("weather"))
                            {
                                reader.Read();
                                weather1 = reader.Value;
                            }
                            else if (reader.Name.Equals("temp_c"))
                            {
                                reader.Read();
                                temperature_string = reader.Value;
                            }
                            else if (reader.Name.Equals("relative_humidity"))
                            {
                                reader.Read();
                                relative_humidity = reader.Value;
                            }
                            else if (reader.Name.Equals("wind_string"))
                            {
                                reader.Read();
                                wind_string = reader.Value;
                            }
                            else if (reader.Name.Equals("pressure_mb"))
                            {
                                reader.Read();
                                pressure_mb = reader.Value;
                            }
                            else if (reader.Name.Equals("dewpoint_string"))
                            {
                                reader.Read();
                                dewpoint_string = reader.Value;
                            }
                            else if (reader.Name.Equals("visibility_km"))
                            {
                                reader.Read();
                                visibility_km = reader.Value;
                            }
                            else if (reader.Name.Equals("latitude"))
                            {
                                reader.Read();
                                latitude = reader.Value;
                            }
                            else if (reader.Name.Equals("longitude"))
                            {
                                reader.Read();
                                longitude = reader.Value;
                            }
                            else if (reader.Name.Equals("feelslike_c"))
                            {
                                reader.Read();
                                feelslike = reader.Value;
                            }

                            break;
                    }
                }
            }

            Console.WriteLine("********************");
            Console.WriteLine("Place:             " + place);
            Console.WriteLine("Observation Time:  " + obs_time);
            Console.WriteLine("Weather:           " + weather1);
            Console.WriteLine("Temperature:       " + temperature_string + "°C");
            Console.WriteLine("Feels Like:        " + feelslike + "°C");
            Console.WriteLine("Relative Humidity: " + relative_humidity);
            Console.WriteLine("Wind:              " + wind_string);
            Console.WriteLine("Pressure (mb):     " + pressure_mb);
            Console.WriteLine("Dewpoint:          " + dewpoint_string);
            Console.WriteLine("Visibility (km):   " + visibility_km);
            Console.WriteLine("Location:          " + longitude + ", " + latitude);
        }

    }
}

Quote:

<response>
<version>0.1</version>
<termsofService>
http://www.wunderground.com/weather/api/d/terms.html
</termsofService>
<features>
<feature>conditions</feature>
</features>
<current_observation>
<image>
<url>
http://icons-ak.wxug.com/graphics/wu2/logo_130x80.png
</url>
<title>Weather Underground</title>
<link>http://www.wunderground.com</link>;
</image>
<display_location>
<full>Cheltenham, United Kingdom</full>
<city>Cheltenham</city>
<state/>
<state_name>United Kingdom</state_name>
<country>UK</country>
<country_iso3166>GB</country_iso3166>
<zip>00000</zip>
<magic>7</magic>
<wmo>03633</wmo>
<latitude>51.90000153</latitude>
<longitude>-2.08333302</longitude>
<elevation>62.00000000</elevation>
</display_location>
<observation_location>
<full>Lansdown - G4GVZ, Cheltenham, GLOUCESTERSHIRE</full>
<city>Lansdown - G4GVZ, Cheltenham</city>
<state>GLOUCESTERSHIRE</state>
<country>UNITED KINGDOM</country>
<country_iso3166>GB</country_iso3166>
<latitude>51.894821</latitude>
<longitude>-2.089248</longitude>
<elevation>243 ft</elevation>
</observation_location>
<estimated></estimated>
<station_id>IGLOUCES14</station_id>
<observation_time>Last Updated on March 19, 10:25 PM GMT</observation_time>
<observation_time_rfc822>Wed, 19 Mar 2014 22:25:20 +0000</observation_time_rfc822>
<observation_epoch>1395267920</observation_epoch>
<local_time_rfc822>Wed, 19 Mar 2014 22:25:36 +0000</local_time_rfc822>
<local_epoch>1395267936</local_epoch>
<local_tz_short>GMT</local_tz_short>
<local_tz_long>Europe/London</local_tz_long>
<local_tz_offset>+0000</local_tz_offset>
<weather>Scattered Clouds</weather>
<temperature_string>47.5 F (8.6 C)</temperature_string>
<temp_f>47.5</temp_f>
<temp_c>8.6</temp_c>
<relative_humidity>91%</relative_humidity>
<wind_string>Calm</wind_string>
<wind_dir>WSW</wind_dir>
<wind_degrees>247</wind_degrees>
<wind_mph>0.0</wind_mph>
<wind_gust_mph>17.0</wind_gust_mph>
<wind_kph>0.0</wind_kph>
<wind_gust_kph>27.4</wind_gust_kph>
<pressure_mb>1019</pressure_mb>
<pressure_in>30.09</pressure_in>
<pressure_trend>+</pressure_trend>
<dewpoint_string>45 F (7 C)</dewpoint_string>
<dewpoint_f>45</dewpoint_f>
<dewpoint_c>7</dewpoint_c>
<heat_index_string>NA</heat_index_string>
<heat_index_f>NA</heat_index_f>
<heat_index_c>NA</heat_index_c>
<windchill_string>48 F (9 C)</windchill_string>
<windchill_f>48</windchill_f>
<windchill_c>9</windchill_c>
<feelslike_string>48 F (9 C)</feelslike_string>
<feelslike_f>48</feelslike_f>
<feelslike_c>9</feelslike_c>
<visibility_mi>6.2</visibility_mi>
<visibility_km>10.0</visibility_km>
<solarradiation/>
<UV>0</UV>
<precip_1hr_string>0.00 in ( 0 mm)</precip_1hr_string>
<precip_1hr_in>0.00</precip_1hr_in>
<precip_1hr_metric>0</precip_1hr_metric>
<precip_today_string>0.00 in (0 mm)</precip_today_string>
<precip_today_in>0.00</precip_today_in>
<precip_today_metric>0</precip_today_metric>
<icon>partlycloudy</icon>
<icon_url>http://icons-ak.wxug.com/i/c/k/nt_partlycloudy.gif</icon_url>;
<forecast_url>
http://www.wunderground.com/global/stations/03633.html
</forecast_url>
<history_url>
http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=IGLOUCES14
</history_url>
<ob_url>
http://www.wunderground.com/cgi-bin/findweather/getForecast?query=51.894821,-2.089248
</ob_url>
</current_observation>
</response>