The Cleveland Guardians had the best ERA by a team in September 2025, with an ERA of 2.52.

	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	Guardians	2.52	September 2025	28	.714	20	8	272	1	8	250.0	195	70	77	20	59	10	1	994	3	9.79	2.12	4.61	0.72	27.4	5.9	1.02	.276	2.77	7.02
2	Pirates	3.07	September 2025	24	.417	10	14	225	0	6	214.0	185	73	83	21	77	8	4	890	10	9.46	3.24	2.92	0.88	25.3	8.7	1.22	.293	3.49	7.78
3	Dodgers	3.32	September 2025	26	.615	16	10	295	0	9	233.1	153	86	89	16	106	8	10	954	14	11.38	4.09	2.78	0.62	30.9	11.1	1.11	.259	3.43	5.90
4	Cubs	3.33	September 2025	26	.577	15	11	228	0	9	230.0	178	85	91	33	51	9	1	910	5	8.92	2.00	4.47	1.29	25.1	5.6	1.00	.246	3.56	6.97
5	Mariners	3.37	September 2025	25	.680	17	8	256	0	7	227.0	194	85	92	26	45	12	2	919	7	10.15	1.78	5.69	1.03	27.9	4.9	1.05	.290	3.65	7.69
6	Brewers	3.46	September 2025	24	.500	12	12	228	0	6	213.1	177	82	94	22	80	14	3	892	4	9.62	3.38	2.85	0.93	25.6	9.0	1.20	.283	3.97	7.47
7	Padres	3.61	September 2025	26	.538	14	12	267	0	6	232.0	200	93	97	38	87	9	4	968	6	10.36	3.38	3.07	1.47	27.6	9.0	1.24	.286	3.76	7.76
8	Phillies	3.70	September 2025	25	.680	17	8	215	0	10	224.0	202	92	97	31	67	6	1	927	7	8.64	2.69	3.21	1.25	23.2	7.2	1.20	.281	3.90	8.12
9	Red Sox	3.70	September 2025	25	.560	14	11	226	0	7	221.1	205	91	101	26	74	6	1	932	13	9.19	3.01	3.05	1.06	24.2	7.9	1.26	.298	4.11	8.34
10	Rangers	3.72	September 2025	24	.417	10	14	203	0	6	217.2	203	90	101	27	57	7	4	899	5	8.39	2.36	3.56	1.12	22.6	6.3	1.19	.291	4.18	8.39
11	Yankees	3.82	September 2025	26	.692	18	8	222	0	8	231.0	194	98	103	26	86	8	1	971	12	8.65	3.35	2.58	1.01	22.9	8.9	1.21	.267	4.01	7.56
12	Blue Jays	3.86	September 2025	25	.600	15	10	214	1	4	221.1	206	95	102	22	83	4	1	938	3	8.70	3.38	2.58	0.89	22.8	8.8	1.31	.299	4.15	8.38
13	Athletics	3.88	September 2025	24	.542	13	11	188	0	5	211.1	193	91	101	27	81	13	6	901	3	8.01	3.45	2.32	1.15	20.9	9.0	1.30	.280	4.30	8.22
14	Orioles	3.90	September 2025	25	.560	14	11	226	0	7	223.2	200	97	105	30	84	6	5	931	13	9.09	3.38	2.69	1.21	24.3	9.0	1.27	.291	4.23	8.05
15	Astros	4.07	September 2025	25	.480	12	13	208	0	5	221.1	199	100	108	36	77	2	0	927	3	8.46	3.13	2.70	1.46	22.4	8.3	1.25	.270	4.39	8.09
16	Giants	4.15	September 2025	25	.520	13	12	207	0	9	221.0	222	102	115	22	75	14	6	952	7	8.43	3.05	2.76	0.90	21.7	7.9	1.34	.315	4.68	9.04
17	Marlins	4.16	September 2025	25	.560	14	11	215	0	6	227.0	214	105	116	39	73	6	3	967	17	8.52	2.89	2.95	1.55	22.2	7.5	1.26	.276	4.60	8.48
18	Reds	4.18	September 2025	26	.538	14	12	234	1	9	230.1	202	107	113	40	71	15	2	962	6	9.14	2.77	3.30	1.56	24.3	7.4	1.19	.269	4.42	7.89
19	Royals	4.20	September 2025	25	.480	12	13	202	0	6	218.2	194	102	105	31	74	5	1	900	11	8.31	3.05	2.73	1.28	22.4	8.2	1.23	.277	4.32	7.98
20	Rays	4.20	September 2025	26	.385	10	16	237	0	4	227.0	203	106	119	28	85	13	1	963	10	9.40	3.37	2.79	1.11	24.6	8.8	1.27	.292	4.72	8.05
21	Braves	4.23	September 2025	25	.560	14	11	241	0	7	225.2	220	106	113	32	73	12	0	957	5	9.61	2.91	3.30	1.28	25.2	7.6	1.30	.314	4.51	8.77
22	Cardinals	4.39	September 2025	24	.417	10	14	187	0	7	213.1	226	104	118	28	74	8	6	930	7	7.89	3.12	2.53	1.18	20.1	8.0	1.41	.313	4.98	9.53
23	White Sox	4.42	September 2025	25	.440	11	14	230	0	7	217.2	205	107	114	35	88	3	4	928	14	9.51	3.64	2.61	1.45	24.8	9.5	1.35	.297	4.71	8.48
24	Diamondbacks	4.53	September 2025	24	.500	12	12	188	0	4	216.1	201	109	122	31	69	5	1	916	4	7.82	2.87	2.72	1.29	20.5	7.5	1.25	.273	5.08	8.36
25	Tigers	4.63	September 2025	25	.320	8	17	217	0	5	221.2	214	114	121	32	88	7	1	954	8	8.81	3.57	2.47	1.30	22.7	9.2	1.36	.298	4.91	8.69