i don't see any error but my time label's don't show up on the weather app

class ViewController: UIViewController {

    var dailyWeather: DailyWeather? {
        didSet {
            configureView()
        }
    }
    @IBOutlet weak var weatherIcon: UIImageView?
    @IBOutlet weak var summaryLabel: UILabel?
    @IBOutlet weak var sunriseTimeLabel: UILabel?
    @IBOutlet weak var sunsetTimeLabel: UILabel?
    @IBOutlet weak var lowTemperatureLabel: UILabel?
    @IBOutlet weak var highTemperatureLabel: UILabel?
    @IBOutlet weak var precipitationLabel: UILabel?
    @IBOutlet weak var humidityLabel: UILabel?

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        configureView()
        }

    func configureView() {
        if let weather = dailyWeather {
            self.title = weather.day
            // Update UI with information from the data model
            weatherIcon?.image = weather.largeIcon
            summaryLabel?.text = weather.summary
            sunriseTimeLabel?.text = weather.sunriseTime
            sunsetTimeLabel?.text = weather.sunsetTime

            if let lowTemp = weather.minTemperature,
               let highTemp = weather.maxTemperature,
               let rain = weather.precipChance,
               let humidity = weather.humidity {
                lowTemperatureLabel?.text = "\(lowTemp)º"
                highTemperatureLabel?.text = "\(highTemp)º"
                precipitationLabel?.text = "\(rain)%"
                humidityLabel?.text = "\(humidity)%"

            }
 }

         // Configure nav Bar back button.
        if let buttonFont = UIFont(name: "HelveticaNeue-Thin", size: 20.0) {
            let barButtonAttributesDictionary: [String: AnyObject]? = [
                NSForegroundColorAttributeName: UIColor.whiteColor(),
                NSFontAttributeName: buttonFont
            ]
            UIBarButtonItem.appearance().setTitleTextAttributes(barButtonAttributesDictionary, forState:             .Normal)
        }
        // Update UI with information from the data model
        weatherIcon?.image

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}