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
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	55	41	2.5	8.0	16.0
29
30

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

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