Hazards are events or conditions that could injure people or damage assets. This toolkit is concerned specifically with hazards related to climate and weather, as listed below.




Air Quality

Air quality reflects the abundance of pollution present in air. Pollution is a mix of hazardous substances from both human-made and natural sources. Primary sources of human-made air pollution include vehicle emissions, fuel oils and natural gas to heat homes, by-products of manufacturing and power generation—particularly coal-fueled power plants—and fumes from chemical production. NIEHS


Drought is a deficiency of precipitation over an extended period of time that results in a water shortage. Drought conditions range from dry weather patterns and low water supply to negative impacts on crops and ecosystems and disruptions in supply and demand for various commodities. USDA Climate Hubs

Erosion and Shoreline Recession

Coastal erosion is the process by which local sea level rise, strong wave action, and coastal flooding wear down or carry away rocks, soils, and/or sands along the coast. Shorelines recede inland as a result of coastal erosion. Drought.gov

Extreme Cold

A cold wave is a rapid fall in temperature within 24 hours and extreme low temperatures that last for an extended period. The temperatures classified as a cold wave are dependent on the location and defined by each local National Weather Service Weather Forecast Office. Extreme cold is sometimes accompanied by winter storm events in which the main types of precipitation are snow, sleet, or freezing rain. FEMA

Extreme Heat

A heat wave is a period of abnormally and uncomfortably hot and unusually humid weather, typically lasting two or more days with temperatures above the historical averages for a given area. FEMA

Flooding - Coastal

Coastal Flooding occurs when water covers normally dry coastal land. Flooding may be a result of high or rising tides or storm surges. FEMA

Flooding - General

Riverine flooding occurs when streams or rivers exceed the capacity of their natural or constructed channels to accommodate the flow of water. Flooding occurs when water overflows river banks, spilling out into adjacent low-lying, usually dry land. FEMA

Flooding - Rainfall-induced

Flash flooding refers to high flowing water or inundation that begins within 6 hours of heavy rainfall. Flash floods generally occur along existing water channels or around existing water sources, including along coastlines. FEMA

High Winds

Strong Winds, often originating from thunderstorms, include event with wind speeds classified as exceeding 58 mph. High winds are associated with hurricanes, tropical storms, tornadoes and other events. High winds have the potential to cause structural damage and electricity blackouts through downed power lines. FEMA

Multiple or Compound Hazards

Compound events result when multiple climate hazards occur close together in space or time. Such events often result in greater impacts than isolated hazards. Compound events can also result from the intersection of climate hazards with other environmental conditions such as pollution, non-climate hazards such as wars and pandemics, or socioeconomic stressors such as poverty and lack of adequate housing. NCA

Severe Winter Weather

Winter weather encompasses winter storm events with lower-than-usual temperatures. The main types of precipitation are snow, sleet, or freezing rain. FEMA

Shifting Species, Habitats, and Ecosystems

Changes in temperature and precipitation affect where species can live, how they interact, and the timing of biological events. Ecosystem changes can be driven by physical factors such as thermal stress, biological responses such as changing ranges, or both. These often interact with stressors from human activities. Multiple stressors can have complex interactive or amplifying effects on ecosystems. NCA

Vector-borne Disease

Diseases transmitted to humans and other animals by blood-feeding species such as mosquitoes, ticks, and fleas are vector-borne diseases. Examples include Dengue fever, West Nile Virus, Lyme disease, and malaria. LA County Public Health

Water Quality

Surface waters and aquifers can be contaminated by various chemicals, ocean water, microbes, and radionuclides. Common sources of drinking water contaminants include industry and agriculture, human and animal waste, treatment and distribution processes, and natural sources.  EPA


Wildfires are unplanned fires burning in natural or wildland areas such as forests, shrub lands, grasslands, or prairies. Wildfires also occur within wildland-urban interfaces—areas where homes and other human structures intermingle with wildland vegetation. FEMA




Last modified: 19 April 2024