How to reduce complexity of 27 by replacing if/else block to something else in React-CodePudding

I have a weather display with emojis adjusted by if/else statement, but there is a major delay evidently since the complexity is 27, how do I replace such method with a replacement that would reduce complexity?

Sort of new to front-end world, any help is much appreciated.

  function drawWeather( d ) {
  var celcius = Math.round(parseFloat(d.main.temp)-273.15);
  var fahrenheit = 
  Math.round(((parseFloat(d.main.temp)-273.15)*1.8) 32);
  var main_description = d.weather[0].main; 
  var description = d.weather[0].description; 

  var day_time = isDay()

  document.getElementById('location').innerHTML = d.name;

  if       ( main_description === 'Clear' && day_time == true) {
  document.getElementById('temp').innerHTML = fahrenheit   
  '&deg;'   ' ☀️';
  } else if ( main_description === 'Clear' && day_time == false) 
  {
  document.getElementById('temp').innerHTML = fahrenheit   
  '&deg;'   '