Chart.js

<canvas id="lineChart" height="340" width="730" style="display: block; width: 730px; height: 340px;"></canvas>
            <script type="application/javascript">
                $(function () {
                    let data = {"Warszawa":{"5":69,"4":56,"3":22,"2":77,"1":50},"Krak\u00f3w":{"5":51,"4":19,"3":25,"2":70,"1":50},"Pozna\u0144":{"5":21,"2":60,"1":40}};
                    let obj = [];
                    for (let d in data) {
                        if (data.hasOwnProperty(d)) {
                            obj.push({
                                label: 'Ilość ogłoszeń - '+d,
                                backgroundColor: 'rgba(255,0,0,1.0)',
                                borderColor: "rgba(26,179,148,0.7)",
                                pointBackgroundColor: "rgba(26,179,148,1)",
                                pointBorderColor: "#fff",
                                data: data[d]
                            });
                        }
                    }
                    let lineData = {
                        labels: ["poniedziałek", "wtorek", "środa", "czwartek", "piątek", "sobota", "niedziela"],
                        datasets: []
                    };
                    let lineOptions = {
                        responsive: true
                    };
                    let ctx = document.getElementById("lineChart").getContext("2d");
                    let datas = [];
                    for (let i=0;i<obj.length;i++){
                        datas[i] = obj[i];
                    }
                    let chart = new Chart(ctx, {type: 'line', data: lineData, options:lineOptions});
                    chart.data.datasets = datas;
                    chart.update();
                });
            </script>