# "Temperature feel" and evaporation

1. Jan 18, 2016

### Ronny33344

Is there a formula relating "temperature feel" to measured temperature and evaporation of water in an evaporation pan (in mm)?
I have data on:
*average temperature
*evaporation of water in an evaporation pan
*minimum temperature of water in an evaporation pan
*maximum temperature of water in an evaporation pan

I want to somehow calculate or approximate "temperature feel" for hot days, something like the temperature-humidity index. Is that possible from this data?

Last edited by a moderator: Jan 18, 2016
2. Jan 18, 2016

### Ronny33344

Also, why is my text so big compared to everyone else's?

3. Jan 18, 2016

### Staff: Mentor

Your copy/pasted text included BBcode formatting tags. I've removed them for you

4. Jan 18, 2016

### Staff: Mentor

The question is not ridiculous, but it is not straightforward either. First you would need to define what "temperature feel" means because I've never heard of it before. There are, however, measures that attempt to reconcile weather conditions against what you feel, such as heat index and wbgt. You should probably google and read up on them and see if they meet your needs.

5. Jan 19, 2016

### Ronny33344

Heat index and wbgt require relative humidity as an input. I don't have relative humidity in my data. :(

6. Jan 19, 2016

### Ronny33344

Thanks.

7. Jan 24, 2016

### Tom.G

8. Jan 24, 2016

### Staff: Mentor

Sorry, missed the response...
You should be able to calculate RH from your data for the heat index, but wbgt does not require RH -- you should be able to use your data directly.

9. Jan 27, 2016

### Elliot Svensson

If you think of yourself as an instrument for measuring things, then what is "I feel cold" or "I feel hot" measuring? As an engineer, it seems to me that a person doesn't measure temperature but heat transfer, i.e. the passage of thermal energy from your skin and hair to the environment or vice versa.

To me this is confirmed by the experiment with the three cups of water, one cold, one hot, and one lukewarm... when you set your hands in the cold and hot cups for a while, and simultaneously put them both in the lukewarm cup, it seems that the lukewarm cup is either quite hot or quite cold--- but not lukewarm.

I think that this thought I have is also confirmed by how well the measurement of wind chill factor predicts the need for a coat, and that folks are advised to get out of the sun to relieve heatstroke. Both wind and sun don't change the air temperature immediately, but they do change a person's heat transfer.

10. Jan 27, 2016

### Elliot Svensson

For relative humidity I would choose either your minimum or maximum temperature in the evaporating pan as equivalent to "wet bulb temperature". Having re-named your data this way, the equation for relative humidity is super-common, being a well-used calculation by weather people. You will also need barometric pressure, but you may find that assuming constant pressure doesn't really change your analysis.

Is the minimum a daily minimum or a measurement from a different sensor, i.e. perhaps at the bottom instead of the top of the pan?