Shaded, Unshaded Temperatures

[PeaceBlondie]

weather.com says it's 29 degrees now in Chiang Mai. I live near the airport, and assume that's the temp in the shade. My gauge in the house said it was only 24 in the house, so it may read too low. I took the gauge outside in direct sunlight, and it read 44 degrees!

I've often said that when the temp is 40 in the shade, it's more like 50 on a motorcycle on the road. Maybe it's 55!

What does your temp gauge say? Or do you spell it gage?

[sbk]

Its a brisk 25 degree C in the shade at my house. No sun today so probably not a whole lot of difference. But, I have tried this out in the hot season and gotten some extreme temp differences as well. I am sure there is a whole scientific explanation for it, but I prefer the mystery

And actually, PB, I call it a thermometer

[mattias33]

I am sure there is a whole scientific explanation for it, but I prefer the mystery

Sun heating the thermometer?

[Farma]

I have a neat little electronic thermometer made by Temp Tec. It has a remote sensor attached to it that allows me to get inside and outside readings at the same time. It also reads humidity levels.

I place the remote sensor about 1 metre above the ground in sunlight to reduce incorrect reading. The temperature readings between shade and sunlight can be up to 15 degrees C.

Only a couple of months ago in the desert I was getting 45 degree C inside temps with outside temps of 55 C. These readings were fairly accurate as the local met office (less than a kilometer away) was giving outside air temperatures matching the ones my thermometer was reading in sunlight.

How quickly seasons change. It’s currently 25.2c with 30% humidity.

There also seems to be a link between humidity levels and temperature of approximately 2% humidity to 1 degree C. I.E 40c with 50% humidity changes to 41c with 48% humidity.

I’m sure there’s a weather person out there who can explain it all.

Edited November 9, 2007 by Farma

[ZZZ]

Even when you are out in the sun it could be different. Take a bare foot walk on a light colored side walk and then step out on a dark colored asphalt surface and you will notice a big difference.

[CymruAmByth]

We use the EL-USB portable Relative Humidity and Temperature Data Logger for our business.

I took it out with me to play golf the other day (late October) and at 12:00 midday is was a constant 46 degrees Celsius (114.8 Fahrenheit) in direct sunshine.

This piece of equipment is extremely accurate.

I hope this has been of help.

[pampal]

In the middle east, I have seen 57 in the shade and near 75 in the sun.

[slapout]

I have had people tell me they saw pigs fly.. Believe 1/2 of what you see and less of what you read or hear.

[naka]

Temperature is always reported as 'In Shade' temperature.

The exception is the Vladisvostok Tourist Board.

Naka.

Edited November 9, 2007 by naka

[Naam]

I have had people tell me they saw pigs fly.. Believe 1/2 of what you see and less of what you read or hear.

i was in Al-Khobar, Eastern Province of Saudi Arabia in 1977 when ARAMCO recorded the (at that time) highest temperature of 54.3ºC and on one of the weekends at the beach we did indeed fry an egg on the hood of a car. it took 4 minutes and 20 seconds.

by the way, air temperature in the sun never exceeds but is identical to air temperature in the shade. what heats up to higher temps are objects exposed to the sun.

[naka]

I have had people tell me they saw pigs fly.. Believe 1/2 of what you see and less of what you read or hear.

i was in Al-Khobar, Eastern Province of Saudi Arabia in 1977 when ARAMCO recorded the (at that time) highest temperature of 54.3ºC and on one of the weekends at the beach we did indeed fry an egg on the hood of a car. it took 4 minutes and 20 seconds.

by the way, air temperature in the sun never exceeds but is identical to air temperature in the shade. what heats up to higher temps are objects exposed to the sun.

Yes Doctor ... Like ... well ... thermometers !

Naka.

[JetsetBkk]

I have had people tell me they saw pigs fly.. Believe 1/2 of what you see and less of what you read or hear.

i was in Al-Khobar, Eastern Province of Saudi Arabia in 1977 when ARAMCO recorded the (at that time) highest temperature of 54.3ºC and on one of the weekends at the beach we did indeed fry an egg on the hood of a car. it took 4 minutes and 20 seconds.

by the way, air temperature in the sun never exceeds but is identical to air temperature in the shade. what heats up to higher temps are objects exposed to the sun.

Yes Doctor ... Like ... well ... thermometers !

Naka.

So, how do you measure the temperature of air in the sun without getting your measuring device hot?

[Naam]

I have had people tell me they saw pigs fly.. Believe 1/2 of what you see and less of what you read or hear.

i was in Al-Khobar, Eastern Province of Saudi Arabia in 1977 when ARAMCO recorded the (at that time) highest temperature of 54.3ºC and on one of the weekends at the beach we did indeed fry an egg on the hood of a car. it took 4 minutes and 20 seconds.

by the way, air temperature in the sun never exceeds but is identical to air temperature in the shade. what heats up to higher temps are objects exposed to the sun.

Yes Doctor ... Like ... well ... thermometers !

Naka.

So, how do you measure the temperature of air in the sun without getting your measuring device hot?

you can use a digital thermometer that shows the temperature in an instant without heating up the instrument or you don't measure at all and believe me that sun/shade air temperatures are identical.

[madjbs]

So to find the relative temperature in the sun we need to measure how much the human body is heated up by the sun? How do you do that?

[PeaceBlondie]

Since air conducts heat quickly, it makes sense what Naam says, that the actual temp under a shade tree cannot be radically different than air just a meter away. Perhaps what my thermometer picked up - a 15 degree difference - is radiant energy. Nevertheless, there has to be a reason why it feels so much hotter in traffic on a motorcycle, than sitting under a shade tree nearby.

[JetsetBkk]

there has to be a reason why it feels so much hotter in traffic on a motorcycle, than sitting under a shade tree nearby.

Hot car/truck/bus engines and radiators, hot tarmac, hot exhaust fumes, hot air-con outlets, no nice cool green grass in the middle of the road... etc, etc, etc, as Yul Brynner would say :D

or you don't measure at all and believe me that sun/shade air temperatures are identical.

Nah, couldn't possibly do that! We need PROOF!

Since air conducts heat quickly,

Oooh, no it doesn't! You'll put all the woolly jumper makers out of business! But, you did hit on a good way to measure the temperature of air in the sun - you stand in the shade in a breeze, so that your thermometer is recording the temperature of the air coming at it straight from the sunny side. Much better than accepting whatever old Naam says!