This is Transport Canadas info on the subject which is on the John Tullamarine tech site, sorry that table doesnt line up, Im no computer geek!
Figure 9.1—Altitude Correction Chart
COLD TEMPERATURE CORRECTIONS
Pressure altimeters are calibrated to indicate true altitude under ISA conditions. Any deviation from ISA will result in an erroneous reading on the altimeter. In a case when the temperature is higher than the ISA, the true altitude will be higher than the Figure indicated by the altimeter, and the true altitude will be lower when the temperature is lower than the ISA. The altimeter error may be significant, and becomes extremely important when considering obstacle clearances in very cold temperatures.
In conditions of extreme cold weather, pilots should add the values derived from the Altitude Correction Chart to the published procedure altitudes, including minimum sector altitudes and DME arcs, to ensure adequate obstacle clearance. Unless otherwise specified, the destination aerodrome elevation is used as the elevation of the altimeter source.
With respect to altitude corrections, the following procedures apply:
IFR assigned altitudes may be either accepted or refused. Refusal in this case is based upon the pilot’s assessment of temperature effect on obstruction clearance.
IFR assigned altitudes accepted by a pilot shall not be adjusted to compensate for cold temperatures, i.e., if a pilot accepts “maintain 3 000”, an altitude correction shall not be applied to 3 000 ft.
Radar vectoring altitudes assigned by ATC are temperature compensated and require no corrective action by pilots.
When altitude corrections are applied to a published final approach fix crossing altitude, procedure turn or missed approach altitude, pilots should advise ATC how much of a correction is to be applied.
ALTITUDE CORRECTION CHART
Height above the elevation of the altimeter setting sources (feet)
Aerodrome Temperature ˚C 200 300 400 500 600 700 800 900 1000 1500 2000 3000 4000 5000
0 20 20 30 30 40 40 50 50 60 90 120 170 230 290
-10 20 30 40 50 60 70 80 90 100 150 200 290 390 490
-20 30 50 60 70 90 100 120 130 140 210 280 430 570 710
-30 40 60 80 100 120 130 150 170 190 280 380 570 760 950
-40 50 80 100 120 150 170 190 220 240 360 480 720 970 1210
-50 60 90 120 150 180 210 240 270 300 450 600 890 1190 1500
NOTES 1: The corrections have been rounded up to the next 10-ft increment.
2: Values should be added to published minimum IFR altitudes.
3: Temperature values from the reporting station nearest to the position of the aircraft should be used. This is normally the aerodrome.
Example: Aerodrome Elevation 2 262ft Aerodrome Temperature -50˚
ALTITUDE HAA CORRECTION INDICATED ALTITUDE
Procedure Turn 4 000 ft 1 738 ft +521.4 ft1 4 600 ft2
FAF 3 300 ft 1 038 ft +311.4 ft 3 700 ft
MDA Straight-in 2 840 ft 578 ft +173.4 ft 3 020 ft
Circling MDA 2 840 ft 578 ft +173.4 ft 3 020 ft
1 CORRECTION derived as follows:
(2 000 ft at -50˚ error) 600 – (1 500 ft at -50˚error)
450 = 150
Altitude difference of above (2 000 – 1 500) = 500
Error per foot difference (150/500)= .3
HAA = 1 738
Error at 1 738 = (1 738 – 1 500) * 0.3 = 71.4 + 450
(error -50˚ at 1 500) = 521.4
2 INDICATED ALTITUDE derived as follows:
Calculated error at 1 738 from above = 521.4
Procedure-turn altitude (4 000) + error (521.4) = 4 521.4
INDICATED ALTITUDE rounded next higher 100-ft increment = 4 600