暑期是出游出行的集中时段，恰逢中国主汛期和"三伏天"，暴雨、高温、强对流天气频繁发生[1]。为帮助公众科学应对极端天气，国家预警信息发布中心、河海大学水文水资源学院、四川省自然资源厅地质灾害防治处和黑龙江省地震局宣传教育中心等单位针对气象灾害预警、洪水识别、地质灾害防范和地震预警等方面提供了系统的避险指导[1]。
气象预警信号分为四个等级：Ⅳ级（一般、蓝色）、Ⅲ级（较重、黄色）、Ⅱ级（严重、橙色）、Ⅰ级（特别严重、红色）[1]。暴雨黄色预警信号表示6小时内降雨量将达50毫米以上，暴雨红色预警信号则意味着3小时内降雨量将达100毫米以上[1]。公众需学会快速解读预警信息，及时采取避险行动。
洪水的危害往往被人们低估。水深仅及踝（约15厘米）的快速水流就可能将成年人冲倒并卷走，水深及膝（约30厘米）时甚至能冲走一辆小型汽车[1]。在汛期防范中，应遵循"住上不住下、住前不住后"的原则，对于屋后有高陡边坡的房屋，汛期应坚决避免靠山居住或在坡下滞留[1]。此外，各地建立了"上游下雨、中游吹哨、下游开跑"的联动防灾机制，确保预警信息能够有效传导[1]。
地震预警与地震预报不同，预警无法预判地震何时发生，而是在地震发生后利用电磁波快于地震波的原理争取宝贵的避险时间[1]。地震预警等级分为蓝色（预估烈度小于3度）、黄色（3至5度）、橙色（5至7度）和红色（7度及以上）[1]。掌握这些知识对暑期安全出行至关重要。
Summer vacation coincides with China's main flood season and the hottest period of the year, bringing frequent occurrences of torrential rain, extreme heat, and severe convective weather.[1] To guide the public through safe summer travel, disaster prevention experts have compiled critical knowledge on recognizing weather warnings, identifying flood characteristics, preventing geological disasters, and understanding earthquake early warning systems.[1]
Weather warning signals are classified into four levels based on severity: Level IV (general, blue), Level III (moderate, yellow), Level II (severe, orange), and Level I (extremely severe, red).[1] A yellow rainstorm warning indicates that rainfall will reach at least 50 millimeters within six hours, while a red rainstorm warning means 100 millimeters or more of rain is expected within three hours.[1] Understanding these distinctions is crucial for timely evacuation decisions.
The dangers posed by floodwaters should not be underestimated. Water reaching ankle depth—approximately 15 centimeters—can create a swift current powerful enough to knock down and sweep away an adult, while water at knee depth—about 30 centimeters—is capable of washing away a small vehicle.[1] To prevent geological disasters during flood season, residents should follow the principle "live on higher ground, not lower ground; live in front, not behind," avoiding homes located behind steep slopes and refusing to remain in areas below slopes during rainy periods.[1] A coordinated prevention mechanism operates as follows: "rain upstream triggers warnings midstream, prompting evacuation downstream."[1]
Earthquake early warning differs fundamentally from earthquake prediction.[1] Early warning systems cannot forecast when an earthquake will occur but instead exploit the principle that electromagnetic waves travel faster than seismic waves to provide critical seconds or tens of seconds for people to take protective action after an earthquake begins.[1] Earthquake early warning alerts are classified by estimated intensity: blue (less than intensity 3), yellow (intensity 3 to 5), orange (intensity 5 to 7), and red (intensity 7 and above).[1]