Below is a program code that has been supplemented with the integration of the DHT22 sensor and other signal lights for the display of temperature and humidity limits.

#include <ESP8266WiFi.h>
#include <DHT.h>

#define DHTPIN D4
#define DHTTYPE DHT22 // DHT 22 (AM2302)

// Sensor
DHT dht(DHTPIN, DHTTYPE);
long lastSensorTime = 0;
float lastTemperature = 0.0f;
float lastHumidity = 0.0f;

// local hardware
const int leds[]={D0, D1, D2, D3, D5, D6, D7, D8};
const int ledCount = 8;
const int signalTCold = D0;
const int signalTOK = D1;
const int signalTHot = D2;
const int signalHDry = D3;
const int signalHOK = D5;
const int signalHWet = D6;
const int signalFan = D7;
const int signalHeating = D8;
bool activateFan=false;
bool activateHeating=false;

void processInputs() {
 long now = millis();
 float t= dht.readTemperature();
 float h= dht.readHumidity();
 if(!isnan(t) && !isnan(h)) {
   lastSensorTime = now;
   lastTemperature = t;
   lastHumidity = h; 
 }
}

void processOutputs() {
 digitalWrite(signalTCold, LOW);
 digitalWrite(signalTOK, LOW);
 digitalWrite(signalTHot, LOW); 
 if(lastTemperature < 18){
   digitalWrite(signalTCold, HIGH);
 } else if(lastTemperature > 22) {
   digitalWrite(signalTHot, HIGH); 
 } else {
   digitalWrite(signalTOK, HIGH);
 }

 digitalWrite(signalHWet, LOW);
 digitalWrite(signalHOK, LOW);
 digitalWrite(signalHDry, LOW); 
 if(lastHumidity < 50){
   digitalWrite(signalHDry, HIGH);
 } else if(lastHumidity > 60) {
   digitalWrite(signalHWet, HIGH); 
 } else {
   digitalWrite(signalHOK, HIGH);
 }
 digitalWrite(signalFan, activateFan ? HIGH : LOW);
 digitalWrite(signalHeating, activateHeating ? HIGH : LOW);
}

void loop() {
 processInputs();
 processOutputs();
}