U.S. CitiesCity-Data Forum Index
Go Back   City-Data Forum > General Forums > Weather
 [Register]
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
View detailed profile (Advanced) or search
site with Google Custom Search

Search Forums  (Advanced)
Reply Start New Thread
 
Old 02-07-2012, 07:13 PM
 
Location: Top of the South, NZ
19,013 posts, read 16,813,495 times
Reputation: 6551

Advertisements

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.
Rate this post positively Reply With Quote Quick reply to this message

 
Old 02-08-2012, 12:02 AM
B87
 
Location: Surrey/London
11,786 posts, read 9,022,969 times
Reputation: 3063
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.
Rate this post positively Reply With Quote Quick reply to this message
 
Old 02-08-2012, 06:00 AM
 
Location: London, UK
2,702 posts, read 5,595,560 times
Reputation: 1720
Measuring temps in sunlight is totally irrelevant to anything, as the temp will vary according to sun angle, cloud cover, and thermometer color
Rate this post positively Reply With Quote Quick reply to this message
 
Old 02-08-2012, 06:34 AM
nei nei won $500 in our forum's Most Engaging Poster Contest - Thirteenth Edition (Jan-Feb 2015). 

Over $104,000 in prizes has already been given out to active posters on our forum and additional contests are planned
 
Location: Western Massachusetts
46,079 posts, read 47,390,173 times
Reputation: 15053
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 09:16 AM..
Rate this post positively Reply With Quote Quick reply to this message
 
Old 02-08-2012, 07:15 AM
 
Location: Leeds, UK
22,256 posts, read 26,592,866 times
Reputation: 8760
I think you're both missing the point of this thread.. lol
Rate this post positively Reply With Quote Quick reply to this message
 
Old 02-08-2012, 11:15 AM
 
Location: Top of the South, NZ
19,013 posts, read 16,813,495 times
Reputation: 6551
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.
Rate this post positively Reply With Quote Quick reply to this message
 
Old 02-08-2012, 11:30 AM
 
Location: Leeds, UK
22,256 posts, read 26,592,866 times
Reputation: 8760
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
Rate this post positively Reply With Quote Quick reply to this message
 
Old 02-08-2012, 12:18 PM
 
Location: Top of the South, NZ
19,013 posts, read 16,813,495 times
Reputation: 6551
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.
Rate this post positively Reply With Quote Quick reply to this message
 
Old 06-30-2012, 09:06 AM
 
1 posts, read 10,405 times
Reputation: 16
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.
Rate this post positively Reply With Quote Quick reply to this message
 
Old 06-30-2012, 09:14 AM
 
Location: Laurentia
5,593 posts, read 7,173,212 times
Reputation: 2425
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.
Rate this post positively Reply With Quote Quick reply to this message
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.

Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.


Reply
Please update this thread with any new information or opinions. This open thread is still read by thousands of people, so we encourage all additional points of view.

Quick Reply
Message:


Over $104,000 in prizes was already given out to active posters on our forum and additional giveaways are planned!

Go Back   City-Data Forum > General Forums > Weather

All times are GMT -6.

© 2005-2021, Advameg, Inc. · Please obey Forum Rules · Terms of Use and Privacy Policy · Bug Bounty

City-Data.com - Contact Us - Archive 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37 - Top