React rendering a loop inside a loop

Trying to loop inside a loop and getting error: value.forEach is not a function.

Dont know how to write this code inside a render

render(){

    return(
        Object.entries(this.props.detailOras).map(([key, value])=>{

       return(
            <div className="flex-row">
            <div className="flex-cont">
                <div>Laikas</div>
                <div>Temperatūra </div>
                <div>Vėjas</div>  
                <div>Krituliai</div>
            </div>

                {value.forEach(day => {
                    return(
                        <div className="flex-cont">
                            <div>{day.forecastTimeUtc.slice(11,16)}</div>
                                <div>{day.airTemperature} </div>
                                <div>{day.windSpeed}</div>  
                                <div>{day.totalPrecipitation}</div>
                            </div>
                          )
                })}
                     </div>
        )
                }


        ))}