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Old 02-07-2012, 08:13 PM
 
Location: Top of the South, NZ
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Today, the difference between the shade temp and sun temp is about 26C/50F. The shade temp (at about 11am) was 22C/74F, and the same thermometer (a white plastic one) was about 48C/118F 6 minutes later. The thermometer was laying on grass about 30 metres from the nearest concrete/structure.

What is the difference where you are?. Some places will be too hot to measure, because most mercury or alcohol thermometers only go up to 50C, but I'd be interested to know,wherever you are, and if you are able to.

 
Old 02-08-2012, 01:02 AM
B87
 
Location: Surrey/London
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I put a thermometer in direct sun in June once and it read 56C. The air temperature was 33C.

Pretty much every day between April-Oct will get somewhere between 35-60C in direct sunlight.
 
Old 02-08-2012, 07:00 AM
 
Location: London, UK
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Measuring temps in sunlight is totally irrelevant to anything, as the temp will vary according to sun angle, cloud cover, and thermometer color
 
Old 02-08-2012, 07:34 AM
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Location: Western Massachusetts
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I don't think putting your thermometer in direct sunlight measures anything. The sun is a heat source, it's like putting your thermometer near a stove.

And as dhdh said, your reading will vary with sun angle an thermometer color. A black thermometer left out in direct almost vertical sun should heat up quickly.

Last edited by nei; 02-08-2012 at 10:16 AM..
 
Old 02-08-2012, 08:15 AM
 
Location: Leeds, UK
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I think you're both missing the point of this thread.. lol
 
Old 02-08-2012, 12:15 PM
 
Location: Top of the South, NZ
22,219 posts, read 21,478,199 times
Reputation: 7608
Quote:
Originally Posted by dunno what to put here View Post
I think you're both missing the point of this thread.. lol
Well said, dunno what to put here.

I know that it's not really scientific, but would still be interested in any differences. The time of year, and latitude can be taken into consideration. I use a white plastic thermometer, which has the glass touching at only two points (no metal). It should be possible to estimate a typical difference

I have been doing this for a while (with the same thermometer) and am interested to see that, at this time of year, the biggest difference is at about 11 am( solar noon), but in winter it is a about 2.00pm.
 
Old 02-08-2012, 12:30 PM
 
Location: Leeds, UK
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Well, to answer your question, I've noticed similar at night - temperatures with a thermometer/sensor on say concrete or grass at night can get seriously low which is why I often take amateur weather stations on Wunderground.com with a pinch of salt
 
Old 02-08-2012, 01:18 PM
 
Location: Top of the South, NZ
22,219 posts, read 21,478,199 times
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Quote:
Originally Posted by dunno what to put here View Post
Well, to answer your question, I've noticed similar at night - temperatures with a thermometer/sensor on say concrete or grass at night can get seriously low which is why I often take amateur weather stations on Wunderground.com with a pinch of salt
I think most thermometers are sited where they over record temperatures, porches, verandahs etc. I do place a thermometer on the grass on frosty mornings, to see the difference from the air temp(measured at 1.8m/6ft off the ground) and it averages at out 4C/8F.

I have 8 thermometers placed around the property and know where the hot and cold spots are. There is little difference in max temps, but min temps vary greatly. Last year, which had the coldest minimums for a number of years, saw a temp of -4.8C/24F in a gully, but a ridge only 200 metres away was 3C/38F at the same time. All are shade readings.
 
Old 06-30-2012, 10:06 AM
 
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Talking Direct Sun is very important

Hi guys,
We all know the official temperatures are taken in the shade and we know why. In recent time the "how it feels" humidity factor is added to the weather reports. Direct sun is a reality to many folks, and the "95 feels like 97" is not nearly so meaningful if you are unlucky enough to spend time outdoors. It would be very meaningful to add "Direct Sun" to our weather. 95 degrees is mild in the shade feels fairly mild in the Texas summer, but can translate to 110 or 115 if you are forced to be in the sun. I say this is an important weather item that has been missing from our local weather.
 
Old 06-30-2012, 10:14 AM
 
Location: Laurentia
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Adding that to weather reports would be a good idea, as an additional item. There would have to be cooked up some formula to correlate sun strength with the "feels like" increase .

For that matter I'd like to see humidex and heat index, wind chill, dew point, and detailed ceiling information (if available) in all weather reports as well. Many prevailing weather reports and maps don't include nearly enough information. And I'd also like to see the official weather station network grow much denser worldwide.
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