Why did the temp read 130 degrees today?

Question

On the TV news today in So. Calif. I saw this big round thermometer the guy was holding read 107 degrees. Then he put in on the grass and after a while it read 130 degrees!! That's crazy. I am wondering why laying on the grass is that much hotter than when he held it. Any ideas?

Answer 1

Because it was in the sun. I have seen thermometers hit 180 degrees F in the sun in the desert. 130 degrees is peanuts.

Answer 2

It was degrees farenheit since the grass was not boiling.

The temperature was hotter because the sun was shining on the ground heating it up so this caused the higher reading.  

Try touching a black car left in the sun for 3 hours on a hot day, then touch a white car. The black car has absorbed more of the sun's energy, the white one reflects some energy away. The grass has absorbed a lot of energy and is hotter than the air.

Air temperature should always be read in the shade to avoid a false hgh reading.

Answer 3

Was it degrees celsius or degrees farenheit?

Coz if it's farenheit it's not as hot as degrees celsius

Answer 4

hahha

i have no idea what your talking about,

but it sounds pretty crazy.

probably cause im from texas!

Answer 5

Sometimes when it's sitting out in the sun it makes it read higher, the sun makes it feel around 15 degrees warmer.

Answer 6

I'm sorry, but I have to chuckle at our 'Meteorologist' friend's statements.

Every comment that he made is so strange that I have to laugh.

First of all he says,"When the thermometer is above the ground it gets less radiation off the ground from the sun. When you go and put the thermometer on the ground the radiation is directed into the thermometer which gives it no time to cool down. This in which will cause there to be a difference in temperature."

This alone is silly enough in my mind but then continues on to say, "Therefore depending on the season and where you live it can be like 6-20 degrees cooler at 6' above the ground and hotter on the ground because the suns heat is retained by the Earths ground."

Although none of his comments are true, the last statement completely missed the point of your question since you specifically stated that the presenter was originally holding the thermometer in his hand and then laid it on the grass.(NOT the ground or a asphalt covered surface or anything else)!!!

Also, I would presume, that the presenter was NOT holding the thermometer on top of his head when he first showed it to the audience.

I am just under 6feet tall, 5'10 and1/2" the last time I checked and when I hold something in my arms normally to show something it is at about 4 foot above my feet (ground level).

I am of average proportions as far as my arms and legs are concerned for a normal human.(At least my knuckles do not drag on the ground when I walk!)

In order for someone with normal human proportions and hold something in a normal manner and that to be 6 feet off the ground, would require them to be 10 feet tall!

I think they would certainly 'stand out in a crowd'! Don't you?

Now I saw this question a few days ago but really did not want to answer it before I had a chance to do some simple observations to report first.

Today was the first day that it has not rained all day and there was a slight chance that we might get some sunshine.

Well we never did get any sunshine, but between the clouds there were a few minutes of thin cloud cover which nearly resembled sunshine.

At 8:30 this morning I went out to begin my first measurement by placing the thermometer at about 5 feet above the ground in what would have been in shade at the time even if the Sun was shining and after 10 minutes the temperature was reading slightly over 60 degrees. I waited another 15 minutes to check again and it was still the same so I placed it on the ground below and came back 15 minutes later to see that the reading was actually reading slightly less than 60 degrees.

This did not surprise me because I knew it was a few degrees colder overnight and that the ground temperature would have reflected that fact.

I then moved the thermometer to where the sun would shine on it if there was a break in the cloud cover about an hour later I went out and saw that the temperature had gone up to 63 degrees and there was beginning to be some indication of a short break in cloud cover. So I stood there and watched for a couple of minutes and as the sunshine increased, so did the temperature. in a couple of minutes the thermometer was reading 70 degrees although there was never any complete break in cloud cover.

I then supported the thermometer on some cold stone which was still in shade but would soon be available if another break in the clouds did occur later. The temperature soon fell back to 60 degrees.

Eventually I saw some brightness coming through the window and went out to see what was happening, and in 3 or 4 relatively short blasts of near full sunlight (90 seconds maximum) I saw the thermometer climb to 72 degrees.

Since it appeared that this was all of the sunlight I was going to get for the remainder of the day, I placed the thermometer one last time in the shade to see what the actual temperature was and it was still 60 degrees.

This is a very simple experiment that I would encourage everyone to do who hasn't done so already and especially any 'Meteorologists'.

Even though I did not have the ideal conditions on the day of the test, they were sufficient enough to prove a point.

And on a clear day the results would be much more drastic.

As hard as one may try, you can NOT argue with the facts!

Answer 7

There is an easy and simple explanation for this. When the thermometer is above the ground it gets less radiation off the ground from the sun. When you go and put the thermometer on the ground the radiation is directed into the thermometer which gives it no time to cool down. This in which will cause there to be a difference in temperature. Therefore depending on the season and where you live it can be like 6-20 degrees cooler at 6' above the ground and hotter on the ground because the suns heat is retained by the Earths ground.

Answer 8

Because he had a f'cked up thermometer maybe?

Answer 9

It was simply because the thermometer was in direct sunlight, and had nothing to due with the actual temperature of the grass or the air temperature.

You can see the same thing for yourself using any thermometer, even on a day when temperatures are below freezing.

On a sunny winter's day it will only take a few short minutes for the thermometer to raise it's reading quite substantially.

If there is no breeze, you can see it happen right before your very eyes, and 30 or 40 degrees increase could be seen in 2 or 3 minutes.

This is why all official temperature readings are made in the shade.

Otherwise it is not a valid indication of outside temperature.

I am curious about why this was done however.

It seems a bit strange to me.

Answer 10

The thermometer will heat up quite a bit when it is held in the sun for a while.  Official temperature readings of the air temperature are supposed to be made in the shade in order to be accurate.