Simple file to check if your DHT11 works well into Arduino/Wemos D1 mini

dht11.ino

#include <dht11.h>
#define DHT11_PIN D2

dht11 dht;


void setup() {
  Serial.begin(115200);

}

void loop() {
  int chk = dht.read(DHT11_PIN);
  Serial.print("Sensor return code: ");
  Serial.println(chk);

  Serial.print("Read sensor: ");
  switch (chk)
  {
    case DHTLIB_OK: 
      Serial.println("OK"); 
      break;
    case DHTLIB_ERROR_CHECKSUM: 
      Serial.println("Checksum error"); 
      break;
    case DHTLIB_ERROR_TIMEOUT: 
      Serial.println("Timeout error"); 
      break;
    default: 
      Serial.println("Unknown error"); 
      break;
    
  }

  Serial.print("Temperature: ");
  Serial.println(dht.temperature);
  Serial.print("Humidity: ");
  Serial.println(dht.humidity);

  delay(2000);

}