What does ph2.5 mean in the weather forecast?

It means that the pH value of rainwater is 2.5.

Hydrogen ion concentration index refers to the ratio of the total number of hydrogen ions to the total amount of substances in the solution. Commonly known as "pH" or "pH value".

Qualitative methods can be determined by pH indicator and pH test paper, and quantitative pH determination requires pH meter.

Weather forecast (measurement) or meteorological forecast (measurement) is to use modern science and technology to predict the state of the earth's atmosphere in a certain place in the future. Since prehistoric times, human beings have begun to predict the weather and arrange their work and life accordingly (such as agricultural production and military operations). ).

Today's weather forecast is mainly based on the collection of a large number of data (temperature, humidity, wind direction and speed, air pressure, etc.). ), and then use the understanding of atmospheric processes (meteorology) to determine future air changes. Because of the chaos of the atmospheric process and the fact that science has not fully understood the atmospheric process today, there will always be some errors in the weather forecast.

The satellite cloud image of China Central Meteorological Observatory was taken from Fengyun-1 and other meteorological satellites. Using satellite cloud images for analysis can improve the accuracy of weather forecast.

Weather forecast is usually divided into three types: short-term weather forecast (2 ~ 3 days), medium-term weather forecast (4 ~ 9 days) and long-term weather forecast (10 ~ 15 days or more). China CCTV mainly broadcasts short-term weather forecast every day.