The San Diego Padres had the best ERA by a team in May 2023, with an ERA of 3.20.

	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	Padres	3.20	May 2023	26	.385	10	16	213	0	4	230.2	188	82	91	21	78	9	4	944	7	8.31	3.04	2.73	0.82	22.6	8.3	1.15	.268	3.55	7.34
2	Astros	3.29	May 2023	27	.630	17	10	272	1	8	238.0	210	87	91	28	79	10	0	982	4	10.29	2.99	3.44	1.06	27.7	8.0	1.21	.307	3.44	7.94
3	Giants	3.39	May 2023	29	.586	17	12	247	0	14	255.0	224	96	110	23	85	14	4	1,060	13	8.72	3.00	2.91	0.81	23.3	8.0	1.21	.291	3.88	7.91
4	Twins	3.45	May 2023	27	.444	12	15	267	0	3	245.1	207	94	102	28	94	8	10	1,026	9	9.79	3.45	2.84	1.03	26.0	9.2	1.23	.285	3.74	7.59
5	Yankees	3.57	May 2023	29	.655	19	10	254	0	10	264.2	230	105	119	30	105	15	1	1,124	6	8.64	3.57	2.42	1.02	22.6	9.3	1.27	.278	4.05	7.82
6	Guardians	3.65	May 2023	27	.444	12	15	201	0	9	239.0	219	97	107	29	72	10	0	997	5	7.57	2.71	2.79	1.09	20.2	7.2	1.22	.277	4.03	8.25
7	Mariners	3.67	May 2023	28	.607	17	11	257	0	5	250.0	221	102	106	26	54	7	2	1,014	11	9.25	1.94	4.76	0.94	25.3	5.3	1.10	.291	3.82	7.96
8	Diamondbacks	3.85	May 2023	27	.630	17	10	238	0	8	243.1	230	104	119	29	87	4	4	1,030	9	8.80	3.22	2.74	1.07	23.1	8.4	1.30	.299	4.40	8.51
9	Braves	3.94	May 2023	29	.517	15	14	276	0	7	258.0	241	113	129	31	97	15	3	1,103	8	9.63	3.38	2.85	1.08	25.0	8.8	1.31	.307	4.50	8.41
10	Rangers	3.95	May 2023	27	.667	18	9	209	0	6	239.1	221	105	109	31	76	9	2	997	5	7.86	2.86	2.75	1.17	21.0	7.6	1.24	.283	4.10	8.31
11	White Sox	3.96	May 2023	29	.517	15	14	250	0	7	259.0	211	114	123	36	107	13	2	1,087	8	8.69	3.72	2.34	1.25	23.0	9.8	1.23	.257	4.27	7.33
12	Blue Jays	4.00	May 2023	28	.393	11	17	245	1	3	247.2	235	110	125	39	112	12	5	1,079	11	8.90	4.07	2.19	1.42	22.7	10.4	1.40	.292	4.54	8.54
13	Tigers	4.03	May 2023	27	.593	16	11	217	0	8	241.0	239	108	125	28	68	5	3	1,024	9	8.10	2.54	3.19	1.05	21.2	6.6	1.27	.299	4.67	8.93
14	Marlins	4.14	May 2023	27	.481	13	14	267	0	7	241.1	230	111	120	27	103	8	8	1,038	6	9.96	3.84	2.59	1.01	25.7	9.9	1.38	.321	4.48	8.58
15	Cardinals	4.16	May 2023	28	.536	15	13	223	0	9	251.0	264	116	130	25	94	14	1	1,099	10	8.00	3.37	2.37	0.90	20.3	8.6	1.43	.322	4.66	9.47
16	Orioles	4.25	May 2023	28	.571	16	12	244	0	9	256.0	258	121	131	37	93	6	5	1,091	12	8.58	3.27	2.62	1.30	22.4	8.5	1.37	.311	4.61	9.07
17	Rays	4.30	May 2023	29	.586	17	12	233	0	12	255.1	245	122	129	41	93	8	4	1,088	16	8.21	3.28	2.51	1.45	21.4	8.5	1.32	.286	4.55	8.64
18	Red Sox	4.36	May 2023	26	.500	13	13	218	0	7	227.0	214	110	125	37	79	8	2	974	9	8.64	3.13	2.76	1.47	22.4	8.1	1.29	.280	4.96	8.48
19	Nationals	4.40	May 2023	29	.483	14	15	212	0	10	253.2	260	124	138	42	112	8	4	1,119	15	7.52	3.97	1.89	1.49	18.9	10.0	1.47	.293	4.90	9.22
20	Pirates	4.49	May 2023	26	.308	8	18	228	1	1	226.2	219	113	127	29	90	6	2	974	13	9.05	3.57	2.53	1.15	23.4	9.2	1.36	.306	5.04	8.70
21	Dodgers	4.49	May 2023	28	.643	18	10	236	0	7	248.2	224	124	133	38	85	10	6	1,051	7	8.54	3.08	2.78	1.38	22.5	8.1	1.24	.273	4.81	8.11
22	Angels	4.59	May 2023	28	.536	15	13	245	0	8	249.0	252	127	138	34	93	8	8	1,077	16	8.86	3.36	2.63	1.23	22.7	8.6	1.39	.313	4.99	9.11
23	Royals	4.60	May 2023	27	.370	10	17	228	0	3	236.2	221	121	131	23	121	9	2	1,035	17	8.67	4.60	1.88	0.87	22.0	11.7	1.45	.303	4.98	8.40
24	Cubs	4.73	May 2023	28	.357	10	18	212	1	4	247.1	252	130	140	30	78	8	1	1,046	5	7.71	2.84	2.72	1.09	20.3	7.5	1.33	.309	5.09	9.17
25	Mets	4.86	May 2023	29	.483	14	15	234	0	9	252.0	243	136	143	38	93	17	0	1,081	10	8.36	3.32	2.52	1.36	21.6	8.6	1.33	.293	5.11	8.68