Every summer, TV meteorologists across the United States increasingly trumpet the “heat index” as an important headline number. [emphasis, links added]
But that figure — the infamous “feels like” temperature — is a calculated estimate, not the actual air temperature. Its overuse smacks more of sensationalism than scientific clarity.
For example, WFLA in Tampa, Florida, recently announced an all-time record heat index, declaring that “this is the highest heat index ever recorded.”
It wasn’t recorded. It isn’t a measurement. So, that’s false.
The heat index is a formula developed by the U.S. National Weather Service (NWS) based on Robert G. Steadman’s 1979 paper “The Assessment of Sultriness.” Before that, it didn’t exist.
It combines actual air temperature and relative humidity into an approximate “apparent” temperature, as if the humidity were higher or lower.
The heat index equation predicts human-perceived heat, assuming shaded, low-wind conditions, and a generic adult body type — but ignores sunlight, wind, individual physiology, hydration, age, weight, health status, and so on.
All individuals experience heat differently. An elderly person or someone with cardiac issues may overheat faster than a young, fit adult. Yet TV reporters happily label heat index values as if they were actual temperatures.
TV Stations Using Heat Index Instead of Actual Temperature
The heat index — once a useful cautionary figure in weather warnings — has lately morphed into a marketing tool masquerading as “temperature.”
Many stations now forefront the inflated apparent temperature while sidestepping the real air temperature, which matters for energy use, infrastructure, and actual thermal load.
You are increasingly likely to hear “today’s high will be 104°F” even when the real thermometer reads 94°F with high humidity.
Good Morning America’s Ginger Zee recently defended showing heat index prominently, saying: “We show heat index because that is what a human feels … if I were forecasting for inanimate objects … I would keep it with temperature.”
While they do include both values, many local affiliates now broadcast the “feels like” temperature as the lead on main weather graphics, leaving viewers believing that artificially elevated number is real.
You can see other examples of this trend from KPRC-TV and a deeper discussion of the issue at Wired.
Why Using the Heat Index Is Misleading
- The higher value isn’t real: Heat index readings aren’t measured — they’re estimated — and they can overshoot physical plausibility in extreme humidity. For example, the Chicago heat wave underestimated its own severity when the real feel was much higher.
- Misleads public risk perception: Viewers may think it’s 10°F or more hotter than the actual air temperature, confusing clothing choices, outdoor planning, and understanding of actual heating or cooling needs.
- Downplays other factors: Sun exposure, wind, and metabolic heat production are often more relevant than static humidity-based estimates.
In some cases, reporters are trying to link higher heat index values to “climate change.” The Washington Post and Climate Central have attempted this.
But climate change isn’t driving the heat index — city environments are. There is no causal link between global climate change and the heat index formula itself.
That index simply responds to local temperature and humidity at a moment in time. It doesn’t project trends, yet the media frequently implies otherwise.
A far larger factor in urban areas is the Urban Heat Island (UHI) effect.
Cities are 1 to 7°F hotter in daytime and 2 to 5°F warmer at night than surrounding rural zones due to pavement, buildings, reduced vegetation, and anthropogenic heat.
NOAA mapping efforts have recorded UHI hotspots up to 20°F hotter. The EPA likewise emphasizes how thermal differences in urban land surfaces amplify heat risk far beyond background climate trends.
Further, the EPA’s climate indicators and UHI documentation stress that heat waves and urban surfaces, not global temperature alone, are the leading contributors to heat‑related health events.
Meanwhile, irrigation of lawns, widespread planting of non‑native grasses, and increased humidity from residential watering over the past 50 years have contributed to local humidity rises, boosting heat index values.
TV forecasts should lead with the actual air temperature, then show heat index estimates as supplemental. Display both, and don’t hide the ambient number.
Explain that the heat index is a calculated metric, not a thermometer reading. Reinforce that personal risk varies based on health factors and local conditions like shade or wind.
If you’re watching a forecast where the “temperature” is wildly higher than recorded official readings from your NWS office, they’re likely misleading you.
If TV meteorologists truly want to serve public understanding, they need to start labeling the heat index properly, show actual temperature first, and educate viewers on the difference.
Let’s stop pretending calculated “feels like” values are real — and start reporting the actual heat, for real.
Read rest at Western Journal
