November 1915 to March 1916, inclusive was remarkable for the extreme variation in the weather.

November 1915 is the 2nd coldest November on record in the CET listings with a CET of 2.8. Apart from January 1908, it was colder than any January from 1898 to 1916 inclusive.
CET trackometer
1. 7.1
2. 5.9
3. 4.9
4. 4.7
5. 4.6
6. 4.4
7. 4.6
8. 4.6
9. 5.0
10. 5.3
11. 5.3
12. 5.2
13. 5.2
14. 5.2
15. 4.9
16. 4.6
17. 4.3
18. 4.1
19. 3.8
20. 3.7
21. 3.6
22. 3.5
23. 3.4
24. 3.3
25. 3.3
26. 3.2
27. 3.0
28. 2.8
29. 2.7
30. 2.8
The coldest spell occurred in the second half of the month, when an anticyclone became established over the UK bringing extensive severe frosts at night. The CET for the period 14th-29th November was just 0.7
Low minima recorded include Biggar with -12.8C on the 18th and 19th, -11.7C at Hereford on the 27th which led to an ice day being recorded at that station as well as 23 air frosts for that month.
Mean temperatures
Chellaston (Derbys.): 1.6C
Biggar: -0.5C
Camden Square: 4.0C
Ice skating took place on the Tweed and the Nith and at Preston, ice skating commenced on the 18th.

500hpa anomalies

November 1915: good blocking in North Atlantic

After the unsual early season severe cold, it became cyclonic during December 1915. Rain fell in copious amounts especially over England and Wales and it ended up the 4th wettest December on record for these countries with 184.9mm

Rainfall totals in inches
Camden Square recorded 5.64
Arundel 8.42
Hailsham 9.62
Launceston 9.52

December 1915: very cyclonic, no wonder it was so wet

January 1916 was the mildest January on record with a CET of 7.5. There was little frost and snow during the month with maxima often in double figures, 17.2C was recorded at Rhyl on the 6th.

The weather was unsettled especially in the north as Atlantic lows regularly pushed through maintaining the mild martime airflow across the UK throughout the month.

January 1916 CET: 7.5 (+4.0)
CET mean max: 10.3
CET mean min: 4.7
First half: 7.6
Second half: 7.4
Warmest CET maximum day: 13.2
Coldest CET minimum night: -0.5
Scotland: 5.2
Northern Ireland: 6.2
January 1989 was milder than January 1916 for Northern Ireland and Scotland.
Across England and Wales, it was a pretty dry month with an England and Wales rainfall average of 56.6mm

CET trackometer

1.  10.5
2. 10.0
3.  9.6
4.  9.7
5.  9.3
6.  9.2
7.  9.2
8.  8.7
9.  8.4
10. 8.3
11. 8.2
12. 8.1
13. 7.9
14. 7.6
15. 7.6
16. 7.6
17. 7.6
18. 7.7
19. 7.7
20. 7.7
21. 7.8
22. 7.8
23. 7.6
24. 7.6
25. 7.5
26. 7.6
27. 7.6
28. 7.6
29. 7.6
30. 7.6
31. 7.5

Camden Square data for January 1916

Mean Temp: 7.6C (+4.0)
Mean Max: 10.4C (+4.1)
Mean Min: 4.8C (+3.6)
Highest Max: 14C on the 1st
Lowest Max: 6.7C on the 31st
Highest Min: 10.1C on the 22nd
Lowest Min: -1.0C on the 23d

Rainfall total: 33.0mm (-17.8mm)
Sunshine: 33.4hrs
Glenquoich recorded a whopping 743mm of rainfall for this month.

January 1916: Bartlett type set up hence why it was so mild

February 1916 increased in cyclonicity compared to the January and it became very wet again. It is the 6th wettest February on record for England and Wales

Rainfall totals include in inches

Croydon 4.97
Twyford 5.36
Plymouth 5.54
Falmouth 7.63
Bourneville 4.64

On the 21st February 1916, the pressure pattern changed and northerly blocking began bringing cold air and increased snowfalls

February 1916: very cyclonic

This heralded a very cold wintry March with a CET of 3.3C, conditions over the Pennines, Peak District and the Southern Uplands were horrendous with deep snow and drifts.

March 1916: Greenland blocking with greater cyclonicity, hence why it was wet with frequent snowfalls

An amazing period of weather, an unusually cold November, an unusually wet December, an unusually mild January, an unusually wet February and an unusually cold and "wet" March.

4 of them in the top 10 of either CET or the 1772 rainfall series.