Here's proof we got to at least Mile 3.  It was actually very pleasant hiking with light rain off and on.  It only rained heavily while we were taking shelter at Clinton Shack and having lunch.  One of our group discovered an anonymous poem about the weather on the Track.

Rain

Anon: 1984 Milford Track tramper

It rained & rained & rained & rained
The average fall was well maintained
And when the tracks were simply bogs
It started raining cats & dogs.

Afer a drought of half an hour
We had a most refreshing shower
And the most cuious thing of all
A gentle rain began to fall.

Next day was also fairly dry
Save for a deluge from the sky
Which wetted the party to the skin
And after that the rain set in.