Go to the CMP Bookstore and check out their guides, books and CDs on rifle shooting. Concentrate on the Service Rifle Guide and the SDM DVD. Both will give you an ideal on what you are looking for. Both cost $6.95 each. Granted they deal with Service rifles (ARs,) but the principle is the same.
https://estore.odcmp.com/Store/login/login.aspx
I've shot the M1A in 308 for about 35 years in high power at 1000 yards, using pretty much the same round as you're using. A 175 Grn SMK at 2500 - 2600 fps.
The formula you're looking for is R*V/10
R is the range in 100 yards. V is the wind speed in MPH, 10 is the constant for the round you're using.
Lets say you're shooting in a 8 MPH wind at 1000. It would be 10*8 = 80/10 = 8. So in a full value wind you'd turn your sights 8 MOA into the wind.
To determine wind speed you can use the conditions, blowing grass, tree limbs, trees, etc. or Range flags. Wind meters give you an ideal but only at the firing line or where you're standing, not down range.
If you have range flags, pick the one mid to 2/3s distance down range.
If you look at a flag you'll notice its blowing out from the flag pole. As the flag stands out, it creates an angle. Divide that angle by 4. That would give you an estimate the wind speed.
So lets say again you are shooting at 1000 yards. you see the angle of the flag is 40 degrees. 40/4 = 10. Now using the formula above. 10 * 10 = 100/10 = 10 clicks of windage to correct for the wind.
That is full value wind. If the wind is coming from 7-8 O'Clock, or 2 or 10, etc etc that would be a half value wind so using the above example you'd need 5 Min's of correction.
This is just the basics. As you learn, and get experience you'll learn to use mirage which in my opinion is a more accurate method.
The books and what you read here is just a guide. To learn shooting in the wind takes practice, lots and lots of practice.
As to temp. based on the round your using, every 10-15 degree change in temp will move your impact 1 MOA, an increase means the bullet will go faster so you come down one min. if the temp cools down so does the velocity so you add a click.
Light: Sun up sights up, sun down sights down. Meaning if you're shooting in bright sunlight, and clouds move in, come down one minute.
The same as to the difference in the position of the sun. If you start shooting in the morning and the sun is on your left you have one sight setting. So come after noon the sun is on your right. Click to the right one MOA. Click into the sun.
Like I said this is all basic. Everyone sees things different because our eyes are different. The above informant ion worked for me in the 15 or so years I coached the Alaska National Guard Rifle team and it still works in my Instructing CMP GSM Clinics.