The USD/MXN is near the 17.36500 ratio as of this writing, this is a value that has been seen rather consistently for a handful of days and seems to be working as a barometer for the currency pair.
The USD/ZAR is near the 16.53200 ratio as of this writing, but day traders are reminded that South Africa is celebrating their Freedom Day holiday and Forex volumes for the Rand will be extremely thin.