Why does my sun not cast shadows north at noon at different months.

[johngow]

I'm trying to provide shade on an outside covered area and am getting wildly different shadow directions at noon in different months.

I know length of shadow will be very different, but shouldn't the sun cast the shadows in nearly the same north direction at noon any time of the year.

I've entered the longitude and latitude and know which way is north, but shadows are all over the place.  

Can anyone help with this?

[mtldesigns]

3 hours ago, johngow said:

shouldn't the sun cast the shadows in nearly the same north direction at noon any time of the year.

I'm not an astronomist, but I am pretty sure it doesn't.  DST takes a play here too.  Are you like really off on the shadows?  

[Michael_Gia]

6 hours ago, johngow said:

but shouldn't the sun cast the shadows in nearly the same north direction at noon any time of the year.

Earth tilt. 
 

unless it’s during the equinoxes, 3rd week in March and September. 
 

also not a astronomer 

[glennw]

Have you included a sun angle?

Have you used this

 

[robdyck]

Obviously one could regurgitate a simple google search of this topic, but it does seem obvious that one must recognize the difference between solar noon relative to your location and 12:00 pm. At 12:00 pm, the angle of direction from the sun to my house has to be different from the angle from the sun to my neighbor’s house. Okay, that would be a very small difference because of the scale, but 12:00 pm occurs at the same time across my entire time zone. Obviously the sun angle and resulting shadow has to be different from the east side to the west side of that time zone. Chief Architect's sun anlge uses the time, not solar noon. I'm sure you could find a way to determine when solar noon is for your particular location, but that wouldn't provide very meaningful information as the time of solar noon would be slightly different every day. 

I can tell you from my own experience that if your inputs are correct, Chief's shadows are exact...at least at my house they are! I designed my own home in Chief and I've physically measured my shadows on different times and days to compare with Chief's output and they are exact!

[robdyck]

https://gml.noaa.gov/grad/solcalc/

I just checked this for my home and solar noon today is at 1:21 pm. Chief's sun angle only allows 15 minute increments and the results are close enough to consider this verifed. This created a shadow in Chief that is perfectly pointing north.