Room temperature checker

This circuit is a temperature checker.
the right temperature to sleep for a room is between 16 and 19 deg C
the red led lights up if it is too hot in the room, green if it is the right temperature and blue if it is too cold.
here is the code
int sensorPin = A0;
int blueled = 4;
int greenled = 5;
int redled = 7;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
pinMode(blueled,OUTPUT);
pinMode(greenled,OUTPUT);
pinMode(redled,OUTPUT);
}
void loop() {
// put your main code here, to run repeatedly:
int reading = analogRead(sensorPin);
float voltage = reading * 5.0;
voltage/= 1024.0;
Serial.print(voltage);Serial.println("volts");
float temperatureC = (voltage-0.5)*100;
Serial.print(temperatureC);Serial.println("degrees C");
if (temperatureC < 19 && temperatureC > 16) {
digitalWrite(greenled,HIGH);
digitalWrite(blueled,LOW);
digitalWrite(redled,LOW);
}
if (temperatureC < 16) {
digitalWrite(greenled,LOW);
digitalWrite(blueled,HIGH);
digitalWrite(redled,LOW);
}
if (temperatureC > 19 ) {
digitalWrite(greenled,LOW);
digitalWrite(blueled,LOW);
digitalWrite(redled,HIGH);
}
delay(1000);
}