Southern California broils before Turkey Day with 2 dozen record highs

The cause is not apparent.
And just to be clear, the records don’t just go back 15 years.
In 2007 I went to the NWS site that covers my city and looked up the record highs and lows for my city. At that time it would give a table of the record highs and lows for each day of the entire year along the the year it was set (later list included ties). Some of the records were set in the late 1800’s.
List in later years, of course, showed some records broken but they also showed old records changed.
Here’s a comparison of the records changed between 2007 and 2012,

Rocord Lows Comparison						
Newer-'12			Older-'07 (did not include ties)			
7-Jan	-5	1884	Jan-07	-6	1942	New record 1 warmer and 58 years earlier
8-Jan	-9	1968	Jan-08	-12	1942	New record 3 warmer and 37 years later
3-Mar	1	1980	Mar-03	0	1943	New record 3 warmer and 26 years later
13-Mar	5	1960	Mar-13	7	1896	New record 2 cooler and 64 years later
8-May	31	1954	May-08	29	1947	New record 3 warmer and 26 years later
9-May	30	1983	May-09	28	1947	New tied record 2 warmer same year and 19 and 36 years later
	30	1966				
	30	1947				
12-May	35	1976	May-12	34	1941	New record 1 warmer and 45 years later
30-Jun	47	1988	Jun-30	46	1943	New record 1 warmer and 35 years later
12-Jul	51	1973	Jul-12	47	1940	New record 4 warmer and 33 years later
13-Jul	50	1940	Jul-13	44	1940	New record 6 warmer and same year
17-Jul	52	1896	Jul-17	53	1989	New record 1 cooler and 93 years earlier
20-Jul	50	1929	Jul-20	49	1947	New record 1 warmer and 18 years earlier
23-Jul	51	1981	Jul-23	47	1947	New record 4 warmer and 34 years later
24-Jul	53	1985	Jul-24	52	1947	New record 1 warmer and 38 years later
26-Jul	52	1911	Jul-26	50	1946	New record 2 warmer and 35 years later
31-Jul	54	1966	Jul-31	47	1967	New record 7 warmer and 1 years later
19-Aug	49	1977	Aug-19	48	1943	New record 1 warmer and 10, 21 and 34 years later
	49	1964				
	49	1953				
21-Aug	44	1950	Aug-21	43	1940	New record 1 warmer and 10 years later
26-Aug	48	1958	Aug-26	47	1945	New record 1 warmer and 13 years later
27-Aug	46	1968	Aug-27	45	1945	New record 1 warmer and 23 years later
12-Sep	44	1985	Sep-12	42	1940	New record 2 warmer and 15, 27 and 45 years later
	44	1967				
	44	1955				
26-Sep	35	1950	Sep-26	33	1940	New record 2 warmer and 12 earlier and 10 years later
	35	1928				
27-Sep	36	1991	Sep-27	32	1947	New record 4 warmer and 44 years later
29-Sep	32	1961	Sep-29	31	1942	New record 1 warmer and 19 years later
2-Oct	32	1974	Oct-02	31	1946	New record 1 warmer and 38 years earlier and 19 years later
	32	1908				
15-Oct	31	1969	Oct-15	24	1939	New tied record same year but 7 warmer and 22 and 30 years later
	31	1961				
	31	1939				
16-Oct	31	1970	Oct-16	30	1944	New record 1 warmer and 26 years later
24-Nov	8	1950	Nov-24	7	1950	New tied record same year but 1 warmer
29-Nov	3	1887	Nov-29	2	1887	New tied record same year but 1 warmer
4-Dec	8	1976	Dec-04	3	1966	New record 5 warmer and 10 years later
21-Dec	-10	1989	Dec-21	-11	1942	New tied record same year but 1 warmer and 47 years later
	-10	1942				
			31			
?			Dec-05	8	1976	December 5 missing from 2012 list
						
Record Highs comparison						
Newer-April '12			Older-'07 (did not include ties)			
6-Jan	68	1946	Jan-06	69	1946	Same year but "new" record 1*F lower
9-Jan	62	1946	Jan-09	65	1946	Same year but "new" record 3*F lower
31-Jan	66	2002	Jan-31	62	1917	"New" record 4*F higher but not in '07 list
4-Feb	61	1962	Feb-04	66	1946	"New" tied records 5*F lower
4-Feb	61	1991				
23-Mar	81	1907	Mar-23	76	1966	"New" record 5*F higher but not in '07 list
25-Mar	84	1929	Mar-25	85	1945	"New" record 1*F lower
5-Apr	82	1947	Apr-05	83	1947	"New" tied records 1*F lower
5-Apr	82	1988				
6-Apr	83	1929	Apr-06	82	1929	Same year but "new" record 1*F higher
19-Apr	85	1958	Apr-19	86	1941	"New" tied records 1*F lower
19-Apr	85	2002				
16-May	91	1900	May-16	96	1900	Same year but "new" record 5*F lower
30-May	93	1953	May-30	95	1915	"New" record 2*F lower
31-Jul	100	1999	Jul-31	96	1954	"New" record 4*F higher but not in '07 list
11-Aug	96	1926	Aug-11	98	1944	"New" tied records 2*F lower
11-Aug	96	1944				
18-Aug	94	1916	Aug-18	96	1940	"New" tied records 2*F lower
18-Aug	94	1922				
18-Aug	94	1940				
23-Sep	90	1941	Sep-23	91	1945	"New" tied records 1*F lower
23-Sep	90	1945				
23-Sep	90	1961				
9-Oct	88	1939	Oct-09	89	1939	Same year but "new" record 1*F lower
10-Nov	72	1949	Nov-10	71	1998	"New" record 1*F higher but not in '07 list
12-Nov	75	1849	Nov-12	74	1879	"New" record 1*F higher but not in '07 list
12-Dec	65	1949	Dec-12	64	1949	Same year but "new" record 1*F higher
22-Dec	62	1941	Dec-22	63	1941	Same year but "new" record 1*F lower
29-Dec	64	1984	Dec-29	67	1889	"New" record 3*F lower