Weather Forecasting : Basics for Arduino

Weather forecasting aims to predict the state of the atmosphere at a certain time in a certain place or area. This does not only mean weather phenomena that affect the ground but the entire earth’s atmosphere is considered. A weather forecast is a forecast over a longer period, i.e. over several days or even months, up to an entire season. The possibility of such forecasts is currently still very limited but could become a reality in the near future due to improved observation possibilities.

The data on the current state of the atmosphere comes from a network of ground measuring stations that measure wind speed, temperature, air pressure and humidity, as well as precipitation amounts. In addition, data from weather satellites, commercial aircraft and weather ships are also used. The problem is the irregular distribution of these observations and measurements, as well as the fact that there are relatively few measuring stations in less developed countries and over the oceans.

For reasons of computing time and the large amounts of data generated, the air and water masses involved cannot yet be taken into account with satisfactory accuracy. There are too many individual factors at play, the interplay of which cannot be fully analysed to date and will not be possible in the near future. Therefore, local influences such as mountains and their irregularly shaped slopes, effects of different irradiation due to “incorrectly” calculated cloudiness, vegetation (forest to the field) or rock makeup so much that the accuracy for the next 4 to 7 days decreases considerably. The theoretical limit of the weather forecast is now assumed to be 14 days.

In today’s system of weather forecasting, the collected data are sent to a computer through a Data
Acquisition Systems (DAS). Multiple parameters are usually multiplexed, made flat with some algorithm (somewhat like like Kalman Filter stabilizes sensor readings) finally proceeding through a single channel to the computer to show the data.

What the Sensors We Can Use for Arduino-Based Weather Forecasting

For well-known large cities, you can use the Arduino library to fetch weather information from OpenWeather:

This method does not require any sensor. However, to calculate the approximate basic weather forecasting around your house (especially in a place away from a larger city), a system can be developed which is simple to design and includes three different sensors with ESP32:

1. Temperature & humidity sensor (DHT11)
2. Pressure sensor (BMP085) and
3. Accelerometer (ADXL-335) (if you make the system with a gas balloon)

You will also need an RTC module (DS1307) and a TFT-Display. If you use a gas balloon (you must check your local laws) to collect the data then you can use the accelerometer module. The data can be recorded and analyzed on a Raspberry Pi or a powerful server or in an Android smartphone. You’ll need the following libraries for Arduino:

1. Adafruit BMP085 Library
2. Adafruit DHT 11 Library
3. Adafruit ST3375 Library
4. Adafruit Graphics Library
5. RTClib (for Tiny RTC Module)

The diagram is from :

Here is a sample sketch:

You can also include soil moisture sensor and rain sensor.