Dark clouds gather.  Lightning splits the sky. The wind gusts and waves crash. Drops of rain become torrential. Are you ready for the storm? Did you receive the weather warnings? Are you acting on good, sound advice? Do you stay put or evacuate?

An early warning is a major element of disaster risk reduction. Multi-hazard early warnings simultaneously address flooding, storms and other major hazards. Long before such hazards arise, early warning projects prepare those at risk as well as those who may be involved in providing assistance so that they will be weather-ready when warnings sound. Impact-based early warning provide more understandable information to those that need to act on the warnings.

To be effective, early warning systems need to actively involve the people and communities at risk. Impact-based, multi-hazard early warning systems incorporate communities, political leadership, weather forecasters, disseminators of warnings, media, emergency response authorities, health facilities and recovery plans. By ensuring strong coordination among all relevant stakeholders, they are more effective and cost-efficient than stand-alone, single-hazard systems.

Multi-Hazard Early Warning Systems: A Checklist

Early warning is a major element of disaster risk reduction. It can prevent loss of life and reduce the economic and material impacts of hazardous events including disasters. To be effective, early warning systems need to actively involve the people and communities at risk from a range of hazards, facilitate public education and awareness of risks, disseminate messages and warnings efficiently and ensure that there is a constant state of preparedness and that early action is enabled.


We need weather forecasts to know what to wear, to plan our day and to prepare for natural hazards that may lie ahead. However, weather forecasts provide essential information for decision-making in many other areas:

FAQs - Weather

Frequently asked questions related to weather events.

Observations - Data - Modelling

Currently, well over 10 000 manned and automatic surface weather stations, 1 000 upper-air stations, 7 000 ships, 100 moored and 1 000 drifting buoys, hundreds of weather radars and 3 000 specially equipped commercial aircraft measure key parameters of the atmosphere, land and ocean surface every day. Add to these some 30 meteorological and 200 research satellites to get an idea of the size of the global network for meteorological, hydrological and other geophysical observations.

Fast Facts

Longest Lasting Tropical Cyclone was 31 days from 10 August 1994 to 10 September 1994 during Hurricane/Typhoon John in Northeast & Northwest Pacific Basins.

Largest Tropical Cyclone (winds from center) Gale winds [17m/s, 34 kt, 39mph] extending 1100km (675 mi) from center on 12 October 1979 during Typhoon Tip in Northwest Pacific Ocean.

Highest Storm Surge ever recorded was 13m (42 feet) on 5 March 1899 during Tropical Cyclone Mahina in Bathurst Bay, Queensland, Australia.

Calendar Month with Greatest number of Tornadoes was May 2003 in the United States with 543 tornadoes.