I don't have anything for this season, but the Boston Celtics had a defensive rating of 113.8 in February 2023.

nba teams defensive rating this season by month february 2023

TEAM	MONTH	DRTG	GP	MPG	PPG	RPG	APG	SPG	BPG	TPG	FGM	FGA	FG%	3PM	3PA	3P%	FTM	FTA	FT%	MIN	PTS	REB	AST	STL	BLK	TOV	PF
Boston Celtics	February	113.8	11	244.5	117.6	46.4	26.2	5.5	4.6	12.3	42.7	87.5	48.8	18.0	43.8	41.1	14.2	17.9	79.2	2,690	1,294	510	288	61	51	135	217
New York Knicks	February	113.1	11	242.3	116.0	45.7	21.5	4.9	3.1	11.2	41.7	86.3	48.4	13.8	37.1	37.3	18.7	25.2	74.4	2,665	1,276	503	237	54	34	123	233
Golden State Warriors	February	116.6	12	242.1	119.5	43.8	30.0	7.2	3.2	14.8	44.2	90.4	48.8	17.1	41.7	41.0	14.1	18.3	76.8	2,905	1,434	525	360	86	38	178	255
Detroit Pistons	February	115.6	10	245.0	107.0	43.0	23.5	6.8	4.5	14.6	39.2	87.2	45.0	10.4	32.3	32.2	18.2	24.1	75.5	2,450	1,070	430	235	68	45	146	231
Los Angeles Lakers	February	113.0	10	240.0	116.2	50.0	26.1	5.9	4.7	14.2	42.6	89.6	47.5	10.3	30.0	34.3	20.7	27.9	74.2	2,400	1,162	500	261	59	47	142	175
Sacramento Kings	February	122.1	12	246.3	125.8	42.2	27.6	8.0	3.5	14.3	45.4	88.1	51.6	13.3	36.3	36.6	21.7	26.3	82.5	2,955	1,509	506	331	96	42	171	230
Philadelphia 76ers	February	114.0	11	240.0	110.5	40.4	23.3	7.2	4.2	11.5	37.3	79.6	46.8	11.3	30.0	37.6	24.6	29.1	84.7	2,640	1,215	444	256	79	46	126	212
Atlanta Hawks	February	117.5	11	240.0	120.3	45.5	26.2	6.6	5.5	11.7	45.6	93.9	48.6	11.5	29.8	38.7	17.5	21.3	82.1	2,640	1,323	500	288	73	61	129	202
Washington Wizards	February	119.7	11	240.0	113.7	41.7	25.0	6.9	4.8	14.4	42.1	83.2	50.6	12.0	31.0	38.7	17.5	21.5	81.8	2,640	1,251	459	275	76	53	158	190
Chicago Bulls	February	107.7	12	240.0	107.4	44.4	23.5	7.2	3.8	13.3	40.8	83.8	48.7	8.7	27.3	31.8	17.3	21.8	79.0	2,880	1,289	533	282	86	45	159	214
San Antonio Spurs	February	118.8	11	244.5	110.2	43.3	25.6	7.5	3.2	15.5	42.4	92.8	45.6	9.5	29.6	32.2	15.9	20.5	77.4	2,690	1,212	476	282	82	35	170	245
Denver Nuggets	February	113.5	12	242.1	119.6	43.9	32.0	7.8	4.4	13.8	45.8	87.8	52.1	12.0	32.4	37.0	16.1	20.8	77.5	2,905	1,435	527	384	94	53	166	211
Indiana Pacers	February	120.4	11	242.3	115.1	39.4	28.2	7.5	5.5	12.4	42.3	88.7	47.6	14.4	38.2	37.6	16.2	21.2	76.4	2,665	1,266	433	310	83	61	136	224
Brooklyn Nets	February	122.5	11	240.0	109.4	38.3	22.3	7.1	4.4	11.9	38.1	84.2	45.2	13.2	36.5	36.1	20.0	23.9	83.7	2,640	1,203	421	245	78	48	131	238
Houston Rockets	February	126.9	11	240.0	110.4	44.5	23.9	6.7	5.4	14.5	40.5	89.5	45.3	8.8	28.3	31.2	20.5	26.6	76.8	2,640	1,214	490	263	74	59	160	229
Oklahoma City Thunder	February	118.4	11	242.3	122.1	42.5	26.0	9.0	3.0	10.9	44.0	94.2	46.7	12.8	36.0	35.6	21.3	25.8	82.4	2,665	1,343	468	286	99	33	120	220
Milwaukee Bucks	February	105.7	10	242.5	118.3	52.0	24.5	5.5	3.8	12.1	44.0	91.9	47.9	15.0	42.2	35.5	15.3	21.5	71.2	2,425	1,183	520	245	55	38	121	189
Phoenix Suns	February	112.8	10	240.0	111.4	46.3	27.1	9.2	4.4	12.8	41.7	88.9	46.9	9.3	29.2	31.8	18.7	24.3	77.0	2,400	1,114	463	271	92	44	128	210
L.A. Clippers	February	118.9	10	250.0	122.3	41.9	24.6	8.5	4.1	13.0	43.4	89.5	48.5	14.0	34.6	40.5	21.5	25.8	83.3	2,500	1,223	419	246	85	41	130	201
Cleveland Cavaliers	February	111.1	11	240.0	115.2	41.1	26.8	8.6	5.0	12.0	43.5	85.2	51.0	11.1	30.8	36.0	17.2	20.9	82.2	2,640	1,267	452	295	95	55	132	199
Portland Trail Blazers	February	125.4	11	240.0	119.0	36.5	24.3	6.2	4.4	12.1	41.3	86.0	48.0	14.6	38.9	37.6	21.8	24.9	87.6	2,640	1,309	401	267	68	48	133	216
Utah Jazz	February	117.6	11	242.3	116.0	49.4	24.5	4.5	6.9	15.9	42.0	90.4	46.5	11.2	35.5	31.5	20.8	26.1	79.8	2,665	1,276	543	269	50	76	175	215
Dallas Mavericks	February	119.1	11	242.3	119.1	39.6	24.8	6.6	3.2	11.5	41.9	86.3	48.6	16.3	41.4	39.3	19.0	24.5	77.7	2,665	1,310	436	273	73	35	127	230
New Orleans Pelicans	February	116.4	10	240.0	111.0	43.0	24.8	8.3	2.8	13.0	41.7	86.7	48.1	9.2	28.2	32.6	18.4	23.2	79.3	2,400	1,110	430	248	83	28	130	217
Miami Heat	February	115.1	10	242.5	105.5	41.0	22.3	7.7	3.8	11.7	37.0	85.4	43.3	10.6	33.9	31.3	20.9	25.1	83.3	2,425	1,055	410	223	77	38	117	199