Growing Degree Days

January 1 to April 15, 2026

Location	Mod 50°F Mod base 50F	2025 GDDs Mod base 50	30-yr avg. 1991-2020	Sine B48 Alfalfa weevil	Mod B40 Onion maggot	Simple B50 Flea beetles, Imported cabbageworm, Squash vine borer	Simple B52 Colorado potato beetle, Corn rootworm adults	Simple B43 Cabbage maggot	Sine B39 Seedcorn maggot	Mod B38 Western bean cutworm
Dubuque IA	264	152	117	251	545	151	120	326	529	613
Lone Rock	212	136		189	456	100	77	226	423	522
Beloit	251	125	114	229	512	122	93	284	487	579
Sullivan	208	108		185	444	92	72	219	413	504
Madison	199	114	107	183	441	99	77	228	416	506
Juneau	173	103		156	398	82	64	182	365	455
Racine	223	106		211	469	106	82	257	443	529
Waukesha	203	99		182	434	91	71	213	404	492
Milwaukee	204	105	83	186	440	93	72	223	409	501
Hartford	177	90	81	161	404	82	64	188	373	460
Appleton	108	55	69	99	287	44	30	124	263	339
Green Bay	94	58	68	81	261	29	18	100	237	313
Big Flats	150	93		135	353	71	54	151	316	405
Hancock	137	75	84	125	331	66	49	142	296	381
Pt Edwards	130	75		119	321	62	46	139	284	369
La Crosse	178	126	119	167	415	97	72	212	393	477
Eau Claire	137	86	89	124	331	66	48	152	304	386
Cumberland	76	53	55	68	220	26	13	92	198	264
Bayfield	27	39		22	126	4	2	27	101	155
Wausau	85	45	69	79	237	37	27	98	208	278
Medford	83	44	53	77	233	33	25	97	206	276
Crivitz	69	50		58	215	21	12	63	181	260
Crandon	53	31		46	179	16	10	56	150	213
Key to GDD calculation methods: Modified B50°F; 2025 Modified B50°F; 30-Year Average 1991-2020; Sine B48°F; Modified B40°F; Simple B50°F; Simple B52°F; Simple B43°F, Sine B39°F; Modified B38°F.