On hot days, home thermometers often show significantly higher temperatures than official weather stations. Why this happens was explained to Ukrainians by the Ukrainian Hydrometeorological Center, reports UNN.
The reason for this "behavior" of the thermometer is that devices in the sun or near heated surfaces record not only the air temperature, but also the influence of solar radiation, asphalt, concrete, metal, or building walls.
Details
In summer, photos of thermometers showing +40°C and higher often appear on social media. At the same time, official meteorological resources may report a significantly lower temperature, for example +30°C. This difference does not mean a mistake by the forecasters.
Solar radiation primarily heats surfaces — asphalt, concrete, roofs, walls, and metal structures. They can heat up much more than the air, and then release heat to the surrounding environment. Therefore, a thermometer on a balcony, near a window, or under direct sunlight shows inflated values.
For accurate measurement of air temperature, meteorologists use psychrometric, or meteorological, screens. They are installed in open areas, away from buildings and trees, and thermometers are placed at a height of about two meters above the ground.
Such screens are painted white, equipped with louvered walls and a double roof. This protects the instruments from direct sunlight and precipitation, but allows air to circulate freely. That is why a weather station measures the air temperature, not that of heated surrounding objects.
Standardized observation conditions make it possible to compare weather data between different regions and countries. In addition, meteorological instruments are regularly checked.
At the same time, the actual temperature and how a person feels it may differ. This is influenced by humidity, wind, sun, and individual characteristics of the body. That is why weather services often indicate the "feels like" index.
So, if a home thermometer shows +45°C, and a weather station shows +30°C, this does not mean the official data is incorrect. Most likely, the home device is under the influence of the sun and heated surfaces, while the weather station records precisely the air temperature.
Reminder
In Europe, they are preparing for new records amid a heatwave. Deadly heat threatens new temperature records in the UK, causing train services to be disrupted and hospitals to prepare for an influx of patients. In France, the heat has already caused the deaths of children and the elderly.