The Colorado Rockies had the worst ERA by a team in June 2023, with an ERA of 6.84.

	TEAM	ERA	MONTH	G	W%	W	L	SO	SHO	SV	IP	H	ER	R	HR	BB	HBP	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	H/9
1	Rockies	6.84	June 2023	27	.333	9	18	206	0	8	235.2	288	179	187	46	111	14	3	1,085	7	7.87	4.24	1.86	1.76	19.0	10.2	1.69	.342	7.14	11.00
2	Royals	5.73	June 2023	26	.231	6	20	186	0	3	226.0	243	144	154	32	84	6	1	987	10	7.41	3.35	2.21	1.27	18.8	8.5	1.45	.311	6.13	9.68
3	Cardinals	5.27	June 2023	23	.348	8	15	165	0	7	201.1	232	118	130	23	76	11	0	904	10	7.38	3.40	2.17	1.03	18.3	8.4	1.53	.332	5.81	10.37
4	Reds	5.03	June 2023	27	.667	18	9	207	0	12	247.0	246	138	145	42	114	17	3	1,095	3	7.54	4.15	1.82	1.53	18.9	10.4	1.46	.285	5.28	8.96
5	Pirates	4.87	June 2023	26	.423	11	15	196	0	8	227.1	240	123	138	26	100	21	4	1,022	3	7.76	3.96	1.96	1.03	19.2	9.8	1.50	.315	5.46	9.50
6	Athletics	4.77	June 2023	26	.385	10	16	213	0	9	230.0	234	122	135	24	102	13	4	1,018	12	8.33	3.99	2.09	0.94	20.9	10.0	1.46	.315	5.28	9.16
7	Nationals	4.77	June 2023	25	.360	9	16	200	0	5	222.2	241	118	128	34	93	9	3	983	9	8.08	3.76	2.15	1.37	20.3	9.5	1.50	.320	5.17	9.74
8	Mariners	4.68	June 2023	24	.375	9	15	212	0	3	211.1	206	110	121	35	74	6	0	899	7	9.03	3.15	2.86	1.49	23.6	8.2	1.32	.299	5.15	8.77
9	Tigers	4.58	June 2023	27	.333	9	18	249	0	3	237.2	225	121	132	34	85	7	2	1,014	10	9.43	3.22	2.93	1.29	24.6	8.4	1.30	.299	5.00	8.52
10	Orioles	4.55	June 2023	24	.542	13	11	238	0	7	213.2	215	108	116	31	67	13	1	926	6	10.02	2.82	3.55	1.31	25.7	7.2	1.32	.319	4.89	9.06
11	Diamondbacks	4.52	June 2023	27	.593	16	11	214	0	7	241.0	246	121	129	28	79	5	2	1,028	6	7.99	2.95	2.71	1.05	20.8	7.7	1.35	.311	4.82	9.19
12	Dodgers	4.46	June 2023	24	.500	12	12	218	0	6	218.0	198	108	115	28	74	13	4	913	11	9.00	3.06	2.95	1.16	23.9	8.1	1.25	.293	4.75	8.17
13	Mets	4.43	June 2023	26	.269	7	19	232	0	2	227.2	227	112	126	34	98	13	3	998	12	9.17	3.87	2.37	1.34	23.2	9.8	1.43	.311	4.98	8.97
14	Astros	4.20	June 2023	27	.481	13	14	215	0	7	244.1	228	114	127	34	97	14	3	1,038	8	7.92	3.57	2.22	1.25	20.7	9.3	1.33	.286	4.68	8.40
15	Angels	4.14	June 2023	27	.519	14	13	254	0	9	239.1	221	110	117	29	99	14	2	1,034	9	9.55	3.72	2.57	1.09	24.6	9.6	1.34	.301	4.40	8.31
16	Rangers	4.13	June 2023	27	.519	14	13	212	0	5	242.0	200	111	116	32	79	11	2	987	4	7.88	2.94	2.68	1.19	21.5	8.0	1.15	.257	4.31	7.44
17	Twins	4.08	June 2023	27	.444	12	15	233	1	5	238.0	216	108	110	31	65	7	3	977	1	8.81	2.46	3.58	1.17	23.8	6.7	1.18	.289	4.16	8.17
18	Braves	3.87	June 2023	25	.840	21	4	248	0	13	225.1	205	97	104	38	78	11	0	948	12	9.91	3.12	3.18	1.52	26.2	8.2	1.26	.291	4.15	8.19
19	Brewers	3.87	June 2023	27	.519	14	13	223	0	9	241.2	202	104	109	33	91	13	1	1,004	8	8.30	3.39	2.45	1.23	22.2	9.1	1.21	.262	4.06	7.52
20	Red Sox	3.82	June 2023	28	.464	13	15	241	0	7	250.0	238	106	115	28	70	10	3	1,042	10	8.68	2.52	3.44	1.01	23.1	6.7	1.23	.303	4.14	8.57
21	Blue Jays	3.80	June 2023	27	.593	16	11	263	0	13	239.0	228	101	105	37	56	10	0	991	5	9.90	2.11	4.70	1.39	26.5	5.7	1.19	.306	3.95	8.59
22	Guardians	3.76	June 2023	26	.538	14	12	218	0	7	234.2	201	98	106	25	96	7	2	996	11	8.36	3.68	2.27	0.96	21.9	9.6	1.27	.271	4.07	7.71
23	Giants	3.55	June 2023	26	.692	18	8	224	0	13	236.0	218	93	99	19	66	14	4	988	7	8.54	2.52	3.39	0.72	22.7	6.7	1.20	.299	3.78	8.31
24	White Sox	3.54	June 2023	26	.500	13	13	269	0	5	231.1	192	91	100	31	94	6	3	979	10	10.47	3.66	2.86	1.21	27.5	9.6	1.24	.278	3.89	7.47
25	Padres	3.52	June 2023	27	.444	12	15	240	0	5	240.1	209	94	107	31	73	11	1	982	10	8.99	2.73	3.29	1.16	24.4	7.4	1.17	.284	4.01	7.83