Bolstering Heat Wave Readiness with NOAA’s HeatRisk Tool

HeatRisk tool helps communities prepare for more frequent and severe heat waves.

Last summer set a record for the hottest temperatures, with climate change driving more frequent and prolonged heat waves, according to the National Oceanic and Atmospheric Administration (NOAA). To help people prepare for high temperatures, NOAA’s National Weather Service (NWS) has expanded its HeatRisk tool to cover the entire contiguous United States.

Understanding the HeatRisk Tool

NOAA and the Centers for Disease Control and Prevention (CDC) launched the HeatRisk tool in California in 2013 and expanded it to other western states 2017. This experimental tool provides a comprehensive view of heat impacts across the country, predicting heat risks from the present up to seven days ahead, allowing communities to better prepare for heat waves.

How HeatRisk Works

Click to expand (chart courtesy of NOAA)

HeatRisk resembles a weather map, with colors indicating different heat risk levels. Light green shows little to no risk, yellow indicates minor risk, orange means moderate, red signifies major, and magenta represents extreme heat levels.

The tool uses temperature data from the NWS and factors in historical temperatures, climate trends, and the duration of high temperatures. Accordingly, in addition to predicting the temperature, the tool can predict how people in the area will likely react based on past patterns.

For example, Maryland residents can typically handle 90°F in August due to their acclimatization to summer heat. However, in April, when average temperatures are usually in the mid-60s, a sudden spike to 90°F can pose severe risks because the population has not yet adjusted to such temperatures.

Factors Influencing Heat Risk

HeatRisk considers various factors beyond just daytime temperatures. Night temperatures play a crucial role; if nights do not cool down, the risk increases without relief from the heat. For example, a 97°F day might fall under major risk in Baltimore, but if it follows several sweltering days without cooling nights, it escalates to extreme risk.

Using HeatRisk

HeatRisk serves state and local governments, healthcare organizations, nonprofits, employers, and individuals. Users can view a seven-day color-coded heat forecast by entering a location and getting detailed information about the risks each day. The tool also guides who faces the highest risks and what precautions to take.

Precautions During Extreme Heat

In areas with extreme heat risk (magenta), everyone, especially those without air conditioning, faces significant danger. People should stay indoors, keep hydrated, and check on vulnerable community members, like the elderly, low-income individuals, and those experiencing homelessness.

NOAA emphasizes that heat impacts vary among individuals and sectors. Factors like health conditions, medications, and acclimatization to the local climate can affect how heat impacts an individual.

Feedback and Future Developments

HeatRisk is still experimental. NOAA continues to refine HeatRisk and welcomes public feedback through September 30.

For more information, visit the NOAA’s NWS HeatRisk tool page.