Let’s take a look at an example METAR with CRFI data in it:

CYFB CRFI 17/35 -22 .34 0201190630

In order, the block of data contains:

Airport/Station Ident
CRFI Indicator
Runway
Temperature
CRFI value
Date/Time reading was taken

So the CRFI for runway 17/35 is 0.34. We can use this value now to figure out how much extra runway we may need on landing. Let’s take a look at Table 1 in the AIM, Section AIR 1.6.6. You can also find the CRFI charts in the CFS.

If your performance calculations indicate that you will need 2000 feet of …