When was the earliest weather forecast in history?

Folk proverbs are the earliest weather forecasts.

People all over the world observe the changes of the weather in their struggle with nature and try to find some laws. Weather proverbs are the experiences about weather changes that spread among the people in the form of idioms or songs.

As early as 3000 years ago, there were many records about meteorology in Oracle Bone Inscriptions of Yin Ruins in China. Jia Sixie of the Northern Wei Dynasty also recorded weather proverbs in Qi Yao Min Shu, such as "It's sunny, but it will be frosty at night". In Du Fu's poems in Tang Dynasty, there is "cuckoo urges spring planting", which means that after cuckoo sings, there is generally no strong cold air influence, and farmers can sow.

There are also some weather proverbs that are worldwide. For example, there is a proverb in China, "Work at sunrise and travel thousands of miles at sunset", which is also widely circulated in Japan. This proverb appears in the United States with another charm: "The sky is red in the evening and sailors are happy."

The experience of ancient people in measuring the sky is the embryonic form of today's weather forecast. Many of these experiences are still circulating among the people and are still used for weather forecasting.

In A.D. 132, during the Eastern Han Dynasty, Zhang Heng invented the world's earliest anemometer-Xiangfeng Copper Bird. This is a 50-foot-high pole on the open ground. The pole is equipped with a flexible rotating copper bird, which can determine the wind direction according to the rotating direction of the copper bird. In ancient times, people mainly predicted the weather based on experience, and the accuracy was very low. With the development of science and technology, there are more and more meteorological instruments and stations all over the country. Now the weather forecast is no longer empirical. It is based on the cloud image sent back by Fengyun-1 meteorological satellite and the meteorological map drawn by the data of temperature, air pressure, wind direction and wind speed measured by various meteorological stations, and is obtained through relevant data and experience judgment. This prediction has always been made manually, which is slow and not very accurate. No wonder some people say: weather forecast is for reference only, you can't believe it, you can't believe it.

In order to accurately forecast the weather, the data obtained above must be listed into hundreds or even higher order linear equations. If it is solved manually, it will take hundreds of people several weeks to complete. This is not a weather forecast, but a weather report. Now that there are electronic computers, the work is done by computers. It only takes a few minutes to finish this task.

The daily weather forecast of CCTV is calculated by the National Meteorological Administration with two large computers.