Wemos D1 mini

- Wifi development board, based on ESP8266EX.

BME280

Temperature, humidity and barometric pressure measurement module from Bosch. The sensor communicates via the I2C interface at speeds up to 3.4 MHz.
Measuring module range and accuracy:
- temperature: -40 to +85 °C, ±1°C
- humidity: 0 to 100%, ±3%
- pressure: 300 to 1100 hPa, ±1Pa

Atmospheric pressure

- force that acts at a given point of the atmosphere perpendicular to any oriented area of (1 m²) unit size. It is caused by the weight of the air column extending from the sea level (or any other elevation level monitored) to the upper limit of the atmosphere.
Air pressure is measured in pascals (Pa), in meteorology, a multiple - hectopascal (1 hPa = 100 Pa) is often used. Atmospheric pressure is influenced by air temperature, atmospheric vapor content, altitude and latitude.

Higher pressure (1 020 to 1 060 hPa)
- during it is nice, sunny, few clouds, usually wind or weak wind. In winter there may be fog, drizzle, it may be very cold.
Pressure lower (below 1000 hPa)
- there are mostly clouds, showers, rain (snow in winter), thunderstorms, stronger winds (pressure below 1000 hPa), and often cool in summer.

Air temperature

- is the ability of air to receive or transmit thermal energy. The air temperature field is considered to be one of the most complex - the temperature often changes in a horizontal direction by a step (eg when the atmospheric front passes). The main cause of temperature variability is the inhomogeneity of the earth's surface.

Humidity

- is a basic meteorological element describing the amount of water vapor in the air. Water vapor, which is concentrated mainly in the lower atmosphere, is formed by evaporation of water surfaces.
The higher the air temperature, the more steam is required to saturate it.