Interesting info taken from http://www.carcraft.com/techarticles/116_0306_nhra/
These charts contain multipliers for elevation only, temp, humidity etc. are a whole different ball game.

NHRA Correction Factors
The Accompanying Charts Are What The NHRA Uses To Convert E.T. And MPH


The accompanying charts are what the NHRA uses to convert e.t. and mph for varying track elevations. To convert your numbers to sea level equivalents, simply multiply the applicable factor by your e.t. and mph. For example, to convert a 12.00 at 112 mph pass at LACR with a 2,700 feet elevation, simply multiply 12.00 by 0.9692 and the 112 mph by 1.0339. The final conversion tells us that our high elevation pass would equate to an 11.63 at 115.80 mph pass at sea level.

 

Good post. Here's some other sites I use to correct my ET/MPH to density altitude to compensate for atmospheric conditions.

Weather conditions for your area including historical weather conditions:

www.wunderground.com

Density altitude calculator:

http://wahiduddin.net/calc/calc_da.htm

Correcting your ET/MPH to density altitude (DA) is an effective and reliable way to gauge gains/losses of mods in varying weather conditions. Any halfway serious 1/4 mile racer uses these formulas.