National Weather Service United States Department of Commerce
Heat Safety and Forecast Information
for Central Pennsylvania

Heat Icon

The National Weather Service has multiple tools to assess the potential for heat stress due to extreme temperatures. Within the following tabs is information that can help understand the issuance of NWS heat watches, warnings, and advisories. Each of these tools integrate other weather parameters to provide a deeper level of information beyond what the actual air temperature can tell us.

Across Central Pennsylvania we experience the conditions most favorable for heat indices reaching dangerously high levels when the winds are out of the west and thunderstorms are unable to form. If this pattern persists over several days or more, this can compound the risk for heat-related illnesses. Please visit for more information.
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Heat Threat Forecast Comparison:
NWS Heat Tools
For more details about each of these "tools", visit:
The National Weather Service's Heat Safety Page
or our detailed Heat Tools Reference Sheet.

Real-time comparison of the three primary Heat Forecast Tools
used by the National Weather Service.
Quick Look: Maximum During the Next 7 Days
  Heat Risk Heat Index Wet Bulb Globe Temp (WBGT)
7 Day Max
These three graphics will not be the same as they are customized for slightly different groups.
(Experimental) HeatRisk
Designed to provide a spectrum of heat-health impacts for ALL populations.
Heat Index
Designed for the general public, primarily people taking part in light physical activity in the shade.
Wet Bulb Globe Temperature
Designed for people engaging in high levels of outdoor physical activity
Daily Forecast for Next 7 Days
  Heat Risk Heat Index Wet Bulb Globe Temp (WBGT)
  Heat Risk Heat Index Wet Bulb Globe Temp (WBGT)

Temperature Probability of Exceedance Forecasts: