Weather forecast accuracy is crucial in a heat wave – 1 degree can mean the difference between life and death

• Even a 1-degree difference in a forecast’s accuracy can be the difference between life and death, our research shows.
• As economists, we have studied how people use forecasts to manage weather risks.
• We found that when the forecasts underplayed the risk, even small forecast errors led to more deaths.

Forecasts that are too mild lead to more deaths

• We examined data on every day’s deaths, weather and National Weather Service forecast in every U.S county from 2005 to 2017 to analyze the impact of those forecasts on human survival.
• We then compared deaths in each county over the week following a day with accurate forecasts to deaths in the same county over the week following a day with inaccurate forecasts but the same weather.
• Both summer days that were hotter than forecast and winter days that were colder had more deaths.

People are paying attention

• People do pay attention to forecasts and adjust their activities.
• The American Time Use Survey, conducted continuously for the U.S. Bureau of Labor Statistics, shows what Americans across the country are doing on any given day.
• That could be due in part to having less flexibility to act on forecasts, or not having access to forecasts.

The value of better forecasts

• So, what is the value of accurate forecasts?
• We combined our theoretical model with federal cost-benefit estimates of how people value improvements in their chances of survival.
• From those, we estimated people’s willingness to pay for better forecasts.
• Past improvements have come from better models, better observations and better computers.