Jan '84 was an exceptionally snowy month from the Midlands northwards, but quite mild with relatively little snow south of the Midlands. Certainly an interesting-sounding month.

But I think January 1958 was even more interesting. It began with a rather chilly NE'ly:

http://www.wetterzentrale.de/archive/ra/19...00119580102.gif

Then the Atlantic came pouring in for about ten days, with some cooler NW'lys interspersed with mild SW'lys and some rough winds:

http://www.wetterzentrale.de/archive/ra/19...00119580107.gif

http://www.wetterzentrale.de/archive/ra/19...00119580109.gif

Then an anticyclonic spell in the third week:

http://www.wetterzentrale.de/archive/ra/19...00119580116.gif

Then a remarkable northerly, assisted by a strong Greenland/Atlantic block, that persisted for a week and brought severe cold and heavy snowfalls from polar lows over much of the country:

http://www.wetterzentrale.de/archive/ra/19...00119580121.gif

Then an exceptional mild end:

http://www.wetterzentrale.de/archive/ra/19...00119580127.gif

We hear a lot about Januarys 1984 and 1987, and rightly so- those months featured some remarkable weather. But for me, the Holy Grail has to be January 1958, as it was the month that had everything.