Green’s Dictionary of Slang

1. (US) increasing in value, improving.

1978		Guardian Weekly 28 May 10/1: Money supply growth for the past year has ended up quite a long way north of the target band – at 16 per cent.
1991		J. Phillips You’ll Never Eat Lunch in this Town Again 162: So Spielberg tells me the budget’s going north [OED].

2. upwards.

2001		‘Randy Everhard’ Tattoo of a Naked Lady 245: I started at her shaved pud and tongued my way north.
2013		J. Stahl Happy Mutant Baby Pills 195: She giggled and moved her hand [...] farther north, to where my brain is supposed to be.

3. in excess of (e.g. in height, weight), older than.

1999		Indep. Rev. 26 July 4: Cost? North of £90.
2009		P. Temple Truth 280: She was north of sixty, overweight, red hair, dyed.
2011		E. Beetner ‘Zed’s Dead, Baby’ in Pulp Ink [ebook] I only get sent on overdue bills north of ten grand.
2015		T. Pluck ‘Moody Joe Shaw’ in Life During Wartime (2018) 243: I’m north of six-and-a-half feet tall.
2016		N.Y. Times 27 Oct. 🌐 Mr. Swick, by his own estimation, also owns ‘north of 30 guns’.
2020		C. Hiaasen Squeeze Me 43: The weight — somewhere north of a hundred-and-fifty pounds.
2021		P Howard Braywatch 152: ‘I need seven grand.’ ‘Yes, of course! [...] I think there’s something north of that figure in the safe!’.