Is the temperature quoted in the shade?

[ganesh]

On forecasts and web-sites is the temp in the shade and haow much would you add on for in the sun ?

[pink-kittens]

it's most likely an average of the 2

However, saying that, generally weather men will say 'it's xx in the shade' but never 'it's xx out in the sun'

[Azalian]

Meteorological measurements are taken using a "Stevenson" screen, a rectangular white louvrered box.

The louvres are designed by limit the flow of air through the box to not more than 2 metres per second to achieve a world standard and of course to shade the thermometers,there are usually two, wet and dry, from direct sunlight.

The white painted box also reflects a large proportion of sunlight.

Thermometers in direct sunlight will get very hot, far hotter that the prevailing air temperature and will not be a true reading of ambient conditions.

Hope this helps.

[ganesh]

Thanks,very scientific though,it's just that when they say it will be max.of 25 degrees,say, at your holiday destination,it actually feels a lot hotter.and the difference in the shade is astonishing.I just wondered roughly,if there was not much breeze,how many degrees hotter it is in the sun to in the shade. I suppose there are too many variables so is there much point quoting a figure anyway?

[Azalian]

Sorry, Ganesh, I meant to post a follow up earlier but forgot.

Same thing applies to the instruments in the Screen, skin (and anything else) in direct sun will feel much hotter than in the shade, a breeze will make you feel cooler (but the sun will still burn you)

The amount of temperature dise for each object will depend on several factors, heat flow, insulation properties of the objects in question, transfer of energy , colour, (dark things heat more than lighter colours) et cetera

The temps quoted on a weather forecast are the air temps taken from a shaded thermometer as above.