Warning levels, I, II, III and IV, are indicated by colors respectively.

The colors of the first, second, third and fourth warning levels are blue, yellow, orange and red respectively.

First of all, blue

1, Blue IV (general): 12 hours, the rainfall will reach more than 50 mm, or it has reached more than 50 mm and the rainfall may continue.

2, blue defense guide:

1) The government and relevant departments should prepare for the rainstorm according to their responsibilities.

2) Schools and kindergartens should take appropriate measures to ensure the safety of students and children.

3) Drivers should pay attention to road water and traffic jams to ensure safety.

4) Check the drainage system of cities, farmland and fish ponds, and prepare for drainage.

Second, yellow.

1, yellow-Ⅲ (heavier): within 6 hours, the rainfall will reach more than 50 mm, or it has reached more than 50 mm and the rainfall may continue.

2, yellow defense guide:

1) The government and relevant departments should do a good job in rainstorm prevention according to their duties.

2) The traffic management department shall take traffic control measures in heavy rainfall sections according to the road conditions, and implement traffic guidance in waterlogged sections.

3) Cut off the dangerous outdoor power supply in low-lying areas, suspend outdoor work in open-air places, and transfer people in dangerous areas and residents in dangerous houses to safe places for shelter from the rain.

4) Check the drainage systems of cities, farmland and fish ponds and take necessary drainage measures.

Third, orange.

1, orange-Ⅱ (severe): within 3 hours, the rainfall will reach more than 50 mm, or it has reached more than 50 mm and the rainfall may continue.

2, orange defense guide:

1) The government and relevant departments shall do a good job in emergency prevention of rainstorm according to their duties.

2) Cut off dangerous outdoor power supply and suspend outdoor operation.

3) Units in dangerous areas should suspend classes and business, and take special measures to protect the safety of students, children and other staff who have arrived at school.

4) Do a good job in the drainage of cities and farmland, and pay attention to prevent possible disasters such as flash floods, landslides and mudslides.

Fourth, red.

1, red-Grade I (especially serious): within 3 hours, the rainfall will reach 100 mm or above, or it has reached 100 mm and the rainfall may continue.

2, the red defense guide:

1) The government and relevant departments should do a good job in emergency rescue against rainstorm according to their duties.

2) Stop the assembly, suspend classes and suspend business (except for special industries).

3) Do a good job in the prevention and rescue of mountain torrents, landslides, mudslides and other disasters.

When a warning signal is issued:

1, have a look

At present, China has popularized a set of comprehensive methods for the release and dissemination of meteorological disaster warning signals, which are composed of names, icons, standards and defense guidelines, and are divided into typhoon, rainstorm, blizzard, cold wave, gale, dust, high temperature, drought, lightning, hail, frost, fog, haze, road icing and so on.

Warning signals of different colors indicate different levels. Generally speaking, there are four colors: blue, yellow, orange and red, which correspond to the degree of harm, urgency and development trend of meteorological disasters, and are divided into four levels (general), three levels (heavier), two levels (serious) and one level (particularly serious).

2. Secondary discrimination

From blue and yellow to orange and red, the same meteorological disaster warning signal has different levels and corresponding defense measures. When the meteorological disaster warning signal is issued, the public should pay attention to the weather changes in time and make reasonable arrangements for travel. It should be noted that the categories and levels of meteorological disaster warning signals vary from place to place. For example, some areas will be affected by typhoons, while others will not. In the same category, there are three levels of "yellow orange red" and four levels of "blue yellow orange red".

This is because China's geographical scope is vast, and the types and scope affected by meteorological disasters vary from place to place. Provinces, autonomous regions and municipalities directly under the Central Government may, according to the characteristics of local meteorological disasters, select or increase the specified types of early warning signals and set different signal standards.