What would I use with the esp8266 to have the temperature displayed on my phone through Blynk
That depends on your level of experience and whether you already have hardware. SparkFun’s Blynk Board has an SI7021 temperature/humidity sensor on the board and comes with built-in software to configure and communicate with Blynk. They have a sample project documented to display the temperature and humidity on an IOS or Android phone through Blynk.
Disadvantages … the ESP8266, voltage regulator, and LEDs warm the board slightly and can throw off the temperature a few degrees.
BME280 sensor in I2C mode
This is a pretty basic setup that I used for a single DS18B20 temperature sensor. In my code, in addition to just sending the temperature, I added a high temp alarm that I can set using the Menu feature in Blynk. However there are many other ways to implement temperature sensing!
What is a BME280? never heard of it.
How will that help me?
Maybe google DS18B20 instead… BME280 might be a bit over the top…
Will I be able to hook it up to my esp8266
probably depends on your wiring skills? can you solder?
yes I can solder …
DS18B20 uses just one wire attached to the ESP, so it should run perfectly fine 
It may require a resistor to display the temperature accurate, but there should be a couple guides on that on the internet. Mine is about 2 degrees C too hot, but it could be placement.
how would I get one? are they at a store or do I have to order one online?
I suggest Ebay it’ll be the cheapest I think, they cost next to nothing.
OK, so your basic sensor options for temperature include:
LM35
DS18B20
DHT11 (also measures humidity)
DHT22 (also measures humidity)
SHT15 (also measures humidity)
Si7021 (also measures humidity)
HTU21D (also measures humidity)
BMP180 (also measures air pressure)
BME280 (also measures humidity & air pressure)
all of these can connect to a micro-processor (like an ESP8266 or Arduino)
thank you for all your suggestions and help
I have a NodeMCU controller, it’s based on ESP8266 and working perfect with Blynk and cheap DHT22 digital temperature/humidity sensor.
Setup is very easy: few wires and one 10Kohm resistor. This is my setup which displays temperature and humidity on my smartphone with Blynk
If you have standalone ESP8266, you can flash it as NodeMCU and program with Arduino IDE.
I have a code for Dht sensor running on esp8266 01 model if you need please reply me.
Hi! Maybe you have a code for bmp180 + dht22?
Thx.
Just go fetch regular Arduino code for these sensors from the 'net and then add the details into a Blynk sketch.