We already have layers for Heat and for Dew Point.

The "Heat Index" is much more intuitive to most users. Please provide this new layer calculated as:

First, get
RH (relative humidity, %):
es = 6.112 * exp(17.67 * T / (T + 243.5))
e = 6.112 * exp(17.67 * D / (D + 243.5))
RH = 100 * e / es
T = air temperature (°C)
D = dew point (°C)

Then heat index (HI, °C):
HI = -8.784695
1.61139411 * T
2.338549 * RH
0.14611605 * T * RH
0.012308094 * T * T
0.016424828 * RH * RH
0.002211732 * T * T * RH
0.00072546 * T * RH * RH
0.000003582 * T * T * RH * RH”

These RH and HI formulas are standard Magnus-type humidity and heat-index polynomials in °C.

I'm guessing US users' preference settings for Fahrenheit will handle that conversion?

If my memory is correct, there used to be a Windy setting that instructed the UI to launch with whichever model was last selected by the user. I don't see that setting in the 30-Jun-2026 build and we need that, or some other way of assigning the launch model.

We all decide which models are most trustworthy in our regions, and it is annoying to have Windy always launch with a model we trust far less.

Thanks for considering.

We already have layers for Heat and for Dew Point.

The "Heat Index" is much more intuitive to most users. Please provide this new layer calculated as:

First, get
RH (relative humidity, %):
es = 6.112 * exp(17.67 * T / (T + 243.5))
e = 6.112 * exp(17.67 * D / (D + 243.5))
RH = 100 * e / es
T = air temperature (°C)
D = dew point (°C)

Then heat index (HI, °C):
HI = -8.784695
1.61139411 * T
2.338549 * RH
0.14611605 * T * RH
0.012308094 * T * T
0.016424828 * RH * RH
0.002211732 * T * T * RH
0.00072546 * T * RH * RH
0.000003582 * T * T * RH * RH”

These RH and HI formulas are standard Magnus-type humidity and heat-index polynomials in °C.

I'm guessing US users' preference settings for Fahrenheit will handle that conversion?