2025 - Northwestern Agricultural Research Center | Montana State University

YEAR 2025 - GROWING DEGREE DAYS JANUARY THROUGH OCTOBER

CALCULATED AT BASE 50, BASE 40, AND BASE 32

January

Temperatures			Growing Degree Days
Day	MAX	MIN	Base 50	Base 40	Base 32
1	33	24	0	0	0.5
2	28	24	0	0	0
3	32	27	0	0	0
4	31	24	0	0	0
5	32	24	0	0	0
6	34	23	0	0	1.0
7	36	18	0	0	2.0
8	30	22	0	0	0
9	29	26	0	0	0
10	31	25	0	0	0
11	34	26	0	0	1.0
12	33	27	0	0	0.5
13	31	24	0	0	0
14	31	25	0	0	0
15	33	17	0	0	0.5
16	30	16	0	0	0
17	28	17	0	0	0
18	27	3	0	0	0
19	18	5	0	0	0
20	25	-3	0	0	0
21	14	0	0	0	0
22	22	3	0	0	0
23	27	10	0	0	0
24	23	10	0	0	0
25	27	-2	0	0	0
26	25	2	0	0	0
27	25	0	0	0	0
28	23	0	0	0	0
29	20	15	0	0	0
30	22	18	0	0	0
31	23	18	0	0	0

	AV MAX	AV MIN	Total Base 50	Total Base 40	Total Base 32

February

Temperatures			Growing Degree Days
Day	MAX	MIN	Base 50	Base 40	Base 32
1	35	21
2	39	14
3	36	5
4	11	2
5	5	3
6	16	4
7	22	4
8	21	11
9	24	7
10	27	3
11	19	-17
12	12	-19
13	12	-12
14	18	-12
15	21	15
16	23	15
17	28	18
18	22	18
19	27	6
20	28	10
21	34	24
22	39	31
23	44	34
24	46	32
25	45	35
26	39	35
27	44	23
28	48	26
29

	AV MAX	AV MIN	Total Base 50	Total Base 40	Total Base 32
	28	12		13.5	52.5

March

Temperatures			Growing Degree Days
Day	MAX	MIN	Base 50	Base 40	Base 32
1	53	23
2	51	22
3	53	24
4	45	27
5	44	31
6	46	24
7	50	19
8	49	24
9	52	33
10	56	39
11	48	32
12	43	32
13	43	31
14	45	29
15	42	27
16	40	27
17	46	31
18	44	29
19	43	27
20	45	24
21	47	33
22	50	32
23	43	31
24	43	33
25	55	42
26	63	32
27	70	32
28	65	40
29	57	35
30	52	26
31	55	26

	AV MAX	AVMIN	Total Base 50	Total Base 40	Total Base 32
	49.6	29.6

April

Temperatures			Growing Degree Days
Day	MAX	MIN	Base 50	Base 40	Base 32
1	53	31	1.5	6.5	10.5
2	37	31	0.0	0.0	2.5
3	46	34	0.0	3.0	8.0
4	41	20	0.0	0.5	4.5
5	45	25	0.0	2.5	6.5
6	54	26	2.0	7.0	11.0
7	62	30	6.0	11.0	15.0
8	54	39	2.0	7.0	14.5
9	56	38	3.0	8.0	15.0
10	57	26	3.5	8.5	12.5
11	68	36	9.0	14.0	20.0
12	62	30	6.0	11.0	15.0
13	54	31	2.0	7.0	11.0
14	53	25	1.5	6.5	10.5
15	60	26	5.0	10.0	14.0
16	71	31	10.5	15.5	19.5
17	50	22	0.0	5.0	9.0
18	51	21	0.5	5.5	9.5
19	57	29	3.5	8.5	12.5
20	50	41	0.0	5.5	13.5
21	58	36	4.0	9.0	15.0
22	47	26	0.0	3.5	7.5
23	53	26	1.5	6.5	10.5
24	59	31	4.5	9.5	13.5
25	65	32	7.5	12.5	16.5
26	70	33	10.0	15.0	19.5
27	68	39	9.0	14.0	21.5
28	69	47	9.5	18.0	26.0
29	64	41	7.0	12.5	20.5
30

	AV MAX	AV MIN	Total Base 50	Total Base 40	Total Base 32
	56.3	31	109.0	243.0	385.0

May

Temperatures			Growing Degree Days
Day	MAX	MIN	Base 50	Base 40	Base 32
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

	AV MAX	AV MIN	Total Base 50	Total Base 40	Total Base 32

June

Temperatures			Growing Degree Days
Day	MAX	MIN	Base 50	Base 40	Base 32
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30

	AV MAX	AV MIN	Total Base 50	Total Base 40	Total Base 32

July

Temperatures			Growing Degree Days
Day	MAX	MIN	Base 50	Base 40	Base 32
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

	AV MAX	AV MIN	Total Base 50	Total Base 40	Total Base 32

August

Temperatures			Growing Degree Days
Day	MAX	MIN	Base 50	Base 40	Base 32
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

	AV MAX	AV MIN	Total Base 50	Total Base 40	Total Base 32

September

Temperatures			Growing Degree Days
Day	MAX	MIN	Base 50	Base 40	Base 32
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30

	AV MAX	AV MIN	Total Base 50	Total Base 40	Total Base 32

October

Temperatures			Growing Degree Days
Day	MAX	MIN	Base 50	Base 40	Base 32
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

	AV MAX	AV MIN	Total Base 50	Total Base 40	Total Base 32