The Oxford English Dictionary (OED – 3rd edition, 2002) defines the British-English phrase black, or dark, over Bill’s, or Will’s, mother’s, and variants, as meaning:
Of the sky, overcast with dark clouds in a specified direction, especially as an indication of coming rain.
And the earliest occurrence of this phrase that the OED has recorded is from Notes and Queries (Oxford University Press) of Saturday 21st June 1930:
There is a very old Sussex saying, when vast clouds appear on the horizon, namely, ‘It looks pretty black over Will’s mother’s.’
However, the two texts containing the earliest occurrences of over Will’s mother’s that I have found indicate that it originally designated the west.
1-: The first text is Golden Glory, published in The Bucks Examiner (Chesham, Buckinghamshire, England) of Friday 26th August 1927:
Residents of this district need no “telling” about the weather of Wednesday. We seemed to run almost the whole gamut of weather experience. A touch of frost, or the feel of frost in the early morning : then a blue sky, sunshine, and warm : suddenly black ominous clouds, and a drenching downpour to greet and bathe (in misery) those going home to the mid-day meal : thunder and lightning : more rain (in buckets and baths full) : rain with intervals until a late hour : intervening, a stormy sunset. Looking from the South over Chesham, the town was bathed in a fiery glow, as if some huge furnace were burning away East and the glow was covering Chesham as a whole. But in an Easterly direction—(“Over Gees,” and not “Over Will’s Mother’s”!)—the real glory was to be seen. The setting sun cast its light back and Mr. Alfred Gee’s cornfields looked at one moment as if they were on fire, so fierce was the red glow; the light softened, and there appeared a golden glow—a real golden glory.
2-: The second text is from Notes of the Week, published in the Bury Free Press (Bury St Edmunds, Suffolk, England) of Saturday 23rd May 1931:
In some of our West Suffolk parishes, of course, we still find “Suffolk as she is spoke,” and one the London newspaper note-writers this week reflects as follows: “Praise of the Suffolk accent has been published recently, and to some extent it is deserved. The East Anglian dialect has a musical quality which is pleasant compared with the harsher tones of other counties. […] The dialect of the Suffolk folk, too, is rich in quaint expressions. For instance, in the village of Lakenheath, where I have often holidayed, the people talk of the west as ‘over Will’s mother’s.’ ‘It’s clouding up over Will’s mother’s,’ they will say. The original Will has long been forgotten, and nobody knows who his mother was or where she lived. It is evident, however, that she must have been locally celebrated and have lived in the west.”
The following is from English—As Spoken in Portsmouth, published in The Evening News (Portsmouth, Hampshire, England) of Wednesday 29th October 1952:
The Hampshire dialect has played its part in fashioning the local argot. Many phrases, full of the parochialism of the countryman, such as “Looks like rain over Will’s mother’s,” are used.
Tony Geraghty quoted a figurative use of the phrase in A cloud over defence, published in The Spectator (London, England) of Saturday 26th March 1977:
As they say in the Midlands when bad tidings are clearly imminent, ‘It’s looking black over Bill’s mother’s place.’
ORIGIN OF THE PHRASE: UNKNOWN
As the above-quoted “London newspaper note-writer” pointed out, the origin of the phrase over Will’s, or Bill’s, mother’s is unknown—which has led to a number of (sometimes ludicrous) hypotheses.
To begin with, it is unlikely that Will’s mother’s refers to a woman who (to quote this “London newspaper note-writer”) “must have been locally celebrated”, since the phrase was in usage in several English counties.
A suggestion occurs in the following letter, from Vol. 4, No. 1, Autumn 1958, of The Amateur Historian (Published by Alden & Blackwell Ltd., Eton College, Windsor, Berkshire):
In North Bedfordshire we use a rather peculiar expression in connection with the weather. Most of our showers and persistent rains come from the south-west; and, when a storm is blowing up from that direction, one often hears people say: ‘We shall soon have rain; it’s getting dark over Will’s Mother’s.’ As to who Will or his mother is, no one seems to have the slightest idea.
The same expression is used in other parts of the county and, I believe, in other parts of the country. I suggest that it is a corruption of some old English phrase, but it is only a suggestion; cf., such corruptions as ‘sparrow-grass’ for ‘asparagus’; ‘causeway’ for ‘chaussée’; ‘crayfish’ for ‘écrevisse’, etc.
Perhaps someone among your readers can throw light on the problem.—C. D. Linnell, Pavenham, Bedford.
(There was no reply to this query in the subsequent issues of The Amateur Historian.)
The following query and reply are from Live Letters, published in the Daily Mirror (London, England) of Thursday 20th April 1978:
B. J. Smith, Ward 2, Burton District Hospital, Burton-on-Trent, Staffs, writes:
● Reclining here in hospital, the usual topic is the weather. The other day a heavy cloud passed by the window and one of my fellow Smiths remarked: “It’s a bit dark over Will’s mother’s.”
Now I have heard this expression many times before when I lived down south in Epsom, but I have never heard the origin of the expression.
Can you help, please?
► ’Fraid not, friend. We’ve heard several variations of the expression, such as “A bit dark over Tom’s mother’s” or “over Aunt Mabel’s,” and it just seems to be a generalisation for “in the near distance.”
Leastways, that’s what we’ve always assumed. Now we suppose we’ll get a letter from the original Will’s mother!
The replies to B. J. Smith’s query appeared in Live Letters, published in the Daily Mirror (London, England) of Tuesday 2nd May 1978:
Willie’s wandering Mum!
What is the origin of the expression “It’s a bit dark over Will’s mother’s,” referring to cloudy weather? We were unable to answer that question put to us recently but, as we guessed, other readers had their own ideas.
G. Cook, Yapton, Sussex writes:
● Among farm workers the sun is known as “Will’s mother,” so when the sun goes behind a cloud “It’s dark over Will’s mother.”
P. Barber, Stephenson Road, Cowes, 10 W, tells us:
● When I was a youngster in the 1930s I lived in a large house in Chalk Farm, London. On the top floor lived a Dolly and Will and the first time I heard “It’s getting dark over Will’s mother’s,” meaning it was going to rain, it was said in all seriousness.
Will’s mother lived in Malden Road on the way to Hampstead. I brought the saying with me to the Isle of Wight.
Mrs. Elizabeth Tyson, Beech Close, Bracebridge Heath, Lincoln, writes:
● Our Lincolnshire version of the saying is: “It’s looking black over our Bill’s tates.”
While Mrs. S. J. Dore, Princes Risborough, Bucks, concludes:
● In a country book called “A Kind of Magic,” authoress Mollie Harris refers to the expression “Round Will’s mother’s way.”
She says it came from a girl who married a fellow called Will from Brize Norton, Oxon, and if the clouds were black and low in that direction she’d say: “That looks black round Will’s mother’s way.”
► With all due respects to Miss Harris, we reckon Will’s Mum must have been a regular moonlight flitter—according to our postbag, she was strictly a lady of no fixed abode!