Why is the real-time temperature far below the lowest predicted temperature in the weather forecast? For example, it was reported at 7- 19℃ today, but the real-time temperature was only 4 degrees in t

Why is the real-time temperature far below the lowest predicted temperature in the weather forecast? For example, it was reported at 7- 19℃ today, but the real-time temperature was only 4 degrees in the morning. The children's shoes on it are wrong. The weather station has reports no matter where it is placed. For example, there are several reference stations in Tianjin, but the temperature in Tianjin is only predicted according to the standard of one reference station. Then why is it called forecast? Because it is never 100% accurate. What's even more ridiculous is that I found that some reported four or five degrees lower, and some even reported eight or nine degrees higher. This is like predicting 14 degrees to 24 degrees. However, the maximum temperature of real-time weather in a whole day does not exceed 15 degrees. Dressing index has short sleeves, but it is the hottest time in the city (12- 17) to wear a thick coat. Not to mention sooner or later, the most ridiculous historical temperature is based on the predicted temperature, not on the all-day real-time temperature. As a result, when I checked the historical temperature, I found that it obviously snowed that day. The historical temperature showed rain or no rain. To be accurate, I have to look at the real-time temperature, but it depends on which cities, and some of them are quite accurate. If I miss my hometown, I may have missed it.