simple-node-weather-api-average

var http    = require('http'),
    cities  = ['Tampa,FL', 'Miami,FL', 'Seattle,WA', 'NewYork,NY', 'Tulsa,OK'],
    weather = [],
    count   = 0,
    port    = 3000,
    tempAvg;

var cityAPIs = cities.map(function(location) {
    return 'http://api.openweathermap.org/data/2.5/weather?q=' + location + '&units=imperial&appid=bd82977b86bf27fb59a04b61b657fb6f';
});


function calAvg() {
    count+=1;
    if(count === cities.length) {
        tempAvg = weather.map(function(str) {
            var data = JSON.parse(str);
            return data.main.temp;
        }).reduce(function(tempPrv, tempNxt) {
            return tempPrv + tempNxt;
        });
        tempAvg = (tempAvg / cities.length + 1).toFixed(1);
    }
}


function getWeather(callback) {
    cityAPIs.forEach(function(url, idx, arr) {
        http.get(url, function(res) {
            weather[idx] = '';
            res.setEncoding('utf8');
            res.on('error', function(error) {
                console.error(error);
            });
            res.on('data', function(data) {
                weather[idx]+=data;
            });
            res.on('end', function() {
                console.log('logged entry ' + idx + '\n' + weather[idx]);
                callback();
            });
        });
    });
}

getWeather(calAvg);

var server = http.createServer(function(req, res) {

    res.writeHead(200, {'Content-Type':'application/json'});
    res.write('{\n\t tempAvg: ' + tempAvg + '\n}', 'utf8');
    res.end();

});

server.listen(port);