Cpaiglesias wrote:
I don't think the sun's altitiualtitude changes noticeably during the day. Maybe it's angle have more to do with it.
I don't think you understand celestial terminology very well.
The Sun's altitude is an angle that expresses the Sun's apparent height in the sky, in a vertical plane, relative to the horizon.. It changes a lot during the day.
The Sun's azimuth is an angle that expresses the Sun's apparent change in latitude, with respect to the horizon, in a horizontal plane on the Earth's surface, going from East to West.
Altitude is the correct term.
When the Sun's altitude is highest the amount of solar radiation hitting the surface is at it's peak. Since the official temperatures are recorded in the shade, the actual ground temperatures will be much hotter then the official recorded readings. Furthermore, as the the Sun's altitude approaches the horizon the amount of solar radiation reaching the surface drops and the actual ground temperatures will be much closer to the official reported temperatures. It should be common sense that racing in 90° at noon, the surface ambient temperature will be much hotter than racing in the same 90° at 7:00pm.