JSFiddle - React, Tailwind, and code Playground

JavaScript

var obj = {
    "forecast": {
        "txt_forecast": {
            "date": "7:52 AM MDT",
                "forecastday": [{
                "period": 0,
                    "icon": "partlycloudy",
                    "icon_url": "http://icons.wxug.com/i/c/k/partlycloudy.gif",
                    "title": "Thursday",
                    "fcttext": "Partly cloudy. High near 90F. Winds W at 10 to 15 mph.",
                    "fcttext_metric": "Sunshine and clouds mixed. High 32C. Winds W at 15 to 25 kph.",
                    "pop": "10"
            }, {
                "period": 1,
                    "icon": "nt_partlycloudy",
                    "icon_url": "http://icons.wxug.com/i/c/k/nt_partlycloudy.gif",
                    "title": "Thursday Night",
                    "fcttext": "Partly cloudy skies. Low 71F. Winds SSE at 5 to 10 mph.",
                    "fcttext_metric": "Partly cloudy. Low 22C. Winds SSE at 10 to 15 kph.",
                    "pop": "0"
            }]
        }
    }
}

console.log(obj.forecast.txt_forecast.forecastday[0].title);