Green’s Dictionary of Slang

colder than... adj.

see also under cold as... adj.

In phrases

...a nun’s snatch (also …a nun’s arse)

(US) extremely cold.

[US]B. Schulberg On the Waterfront (1964) 138: It was winter time an’ the water was colder than a nun’s — well, I mean it was ice water.
[US]D. Jenkins Semi-Tough 52: It can also get colder than a nun’s ass.
[US](con. 1970s) G. Pelecanos King Suckerman (1998) 39: It was colder than a nun’s snatch in there.
...a welldigger’s butt (also …a welldigger’s ass)

(US) very cold.

[US]L. Uris Battle Cry (1964) 68: Colder than a welldigger’s butt out here.
[US]A. Brooke Last Toke 219: Richie shivered, pulled his collar tight at his throat. ‘Colder ’n a well-digger’s ass!’.
[US] M. McBride Frank Sinatra in a Blender [ebook] It was colder than a well digger’s ass in January.
...a witch’s tit (also …a witch’s titty)

1. of weather, very cold.

[UK](con. 1939–45) J. Klaas Maybe I’m Dead 95: It’s – that wind. It’s colder than a witch’s tit.
[US]D. Ponicsan Last Detail 41: It’s colder than a witch’s tit out.
[US]V.E. Smith Jones Men 163: It’s colder’n a witch’s titty in a hailstorm.
[US]H. Gould Fort Apache, The Bronx 160: It was colder than a witch’s tit. The wind stabbed through his coat.
[US]C. Hiaasen Nature Girl 201: That goddam river is colder than a witch’s titty.

2. of emotions, very unfriendly.

[UK]Partridge DSUE (8th edn) 238/2: later C.20.

3. sexually frigid.

[UK]T. Keyes All Night Stand 27: It’s all lies, they are all colder than witches’ tits.