code: def get_weather_forecast(self, latitude, longitude, start, end,
              frequency=1, reading_type=None):
          
          params = {}
  
          # Can get data from NWS1 or NWS3 representing 1-hr and 3-hr
          # intervals.
          if frequency not in [1, 3]:
              raise ValueError("Reading frequency must be 1 or 3")
  
          params['source'] = 'NWS' + str(frequency)
          params['latitude'] = latitude
          params['longitude'] = longitude
          params['start_datetime_utc'] = start
          params['end_datetime_utc'] = end
  
          if reading_type:
              # Not using urllib.quote_plus() because its using a + which is
              # being interpreted by service as an and instead of a space.
              reading_type = reading_type.replace(' ', '%20')
              params['reading_type'] = reading_type
  
          url = self.uri + '/v1/weather-forecast-datetime/'
          return self.service._get(url, params=params)
docs: Return the weather forecast for a given location for specific
          datetime specified in UTC format.
  
          ::
  
              results = ws.get_weather_forecast(lat, long, start, end)
              for w in results['hits']:
                  print w['start_datetime_local']
                  print w['reading_type'], '=', w['reading_value']
  
          For description of reading types:
          https://graphical.weather.gov/xml/docs/elementInputNames.php