Temperature Trends in Portland, Maine

Average daily temperatures in Portland, Maine, including the lower and upper bounds of the 95% confidence interval. Due to the possibility of missing data, the actual day counts used in the average and confidence interval calculations are provided. The table is also offered in degrees of Fahrenheit.

Average daily temperatures (C) for Portland, Maine
Lower BoundAverage TemperatureUpper Bound

	January	February	March	April	May	June	July	August	September	October	November	December
1	-6 -4 -1	-6 -5 -3	-4 -1 1	3 4 6	9 10 12	15 17 19	18 20 21	20 21 22	18 19 21	11 13 15	7 9 11	1 3 6
2	-6 -4 -1	-5 -4 -2	-3 -1 2	3 5 6	9 11 13	15 17 18	19 20 21	20 21 23	17 18 19	11 13 14	5 7 9	-0 2 4
3	-6 -4 -1	-5 -3 -1	-4 -1 1	3 5 6	9 11 13	14 15 17	19 20 22	20 21 23	17 18 19	11 13 14	4 7 9	-1 1 4
4	-6 -3 -1	-6 -4 -1	-4 -2 1	3 5 7	9 11 13	13 14 16	19 21 22	20 21 22	17 19 20	10 12 14	4 6 7	-1 1 3
5	-6 -3 -0	-7 -4 -2	-2 -1 1	2 4 6	10 11 13	13 15 16	20 21 23	20 21 22	17 18 19	10 12 14	4 5 7	-2 1 4
6	-6 -3 -0	-7 -4 -1	-2 -0 2	2 4 6	9 11 12	14 15 16	20 21 23	19 21 22	16 18 19	9 11 13	5 6 8	-2 1 4
7	-5 -2 -0	-7 -5 -2	-3 -1 2	3 5 7	10 11 12	13 15 17	19 20 22	19 20 21	17 18 20	8 10 12	4 6 8	-2 0 3
8	-6 -4 -1	-7 -5 -3	-3 -0 2	3 5 7	10 12 14	14 16 18	18 20 21	19 21 22	17 19 20	9 11 12	5 7 9	-3 -1 1
9	-6 -4 -1	-6 -4 -2	-3 -1 2	4 5 7	10 11 12	15 17 19	18 20 21	20 21 22	17 18 20	10 11 13	3 6 8	-5 -3 -1
10	-6 -3 -0	-4 -2 -1	-3 -1 2	4 6 8	10 11 13	16 17 18	19 20 21	20 22 23	15 17 19	10 12 14	4 6 9	-3 -1 1
11	-7 -4 -2	-5 -4 -2	-2 -0 2	4 5 7	10 11 12	14 16 18	18 20 21	20 21 22	14 16 18	11 12 13	4 6 8	-2 -0 1
12	-6 -3 -1	-7 -4 -2	-0 1 3	4 6 7	10 11 13	15 16 18	19 20 21	19 20 21	15 16 18	9 11 12	3 5 7	-2 -0 2
13	-4 -2 -0	-7 -5 -2	-1 1 3	5 6 8	9 10 12	15 16 18	20 20 21	19 20 21	16 17 18	9 11 12	2 4 6	-3 -1 2
14	-8 -4 -1	-7 -4 -2	-1 1 3	6 7 9	9 10 11	15 16 17	20 21 23	19 20 22	16 17 18	10 11 13	3 5 8	-4 -1 2
15	-10 -6 -3	-6 -3 -1	1 2 4	6 7 9	10 11 12	14 16 18	20 21 23	19 20 21	16 17 19	8 11 13	4 6 9	-4 -1 2
16	-10 -6 -3	-6 -3 -0	-0 1 3	5 7 9	10 11 13	15 16 18	20 21 22	20 21 22	14 15 17	8 10 11	3 5 7	-4 -1 1
17	-8 -5 -2	-5 -3 -1	-1 0 2	6 8 10	10 11 13	15 17 19	20 22 24	20 21 23	13 14 16	8 10 11	2 4 6	-3 -1 1
18	-8 -5 -2	-5 -3 -0	-1 2 4	6 8 10	10 12 13	16 18 20	21 22 24	19 21 22	14 15 16	8 9 10	1 2 4	-4 -2 1
19	-8 -4 -1	-5 -2 0	-0 2 4	7 8 10	11 12 14	17 18 20	20 21 22	19 20 22	13 15 16	7 9 11	0 2 4	-5 -3 -1
20	-6 -3 -1	-3 -1 1	-0 1 3	8 10 12	11 12 14	18 19 21	19 21 22	18 19 20	14 15 17	8 10 12	2 4 6	-4 -2 -0
21	-8 -6 -3	-3 -1 1	-0 2 4	7 8 10	12 14 16	18 19 20	20 21 22	18 19 21	14 16 17	8 10 11	2 3 5	-6 -3 -0
22	-10 -7 -4	-4 -2 1	0 3 5	7 8 10	11 13 14	17 19 20	20 22 23	18 20 21	15 16 17	6 8 10	1 3 4	-4 -1 1
23	-9 -6 -3	-3 -1 1	-0 3 5	7 9 10	11 12 14	17 19 20	20 21 23	19 20 21	15 16 18	5 7 9	0 2 4	-4 -1 1
24	-9 -5 -2	-4 -2 0	1 2 4	8 9 11	12 14 15	17 19 20	19 21 22	18 19 21	13 15 17	6 8 10	-0 2 5	-2 0 2
25	-8 -5 -1	-4 -2 -0	1 2 3	7 9 10	12 14 16	18 20 22	19 20 22	18 19 20	13 14 16	7 9 11	0 3 5	-4 -1 1
26	-9 -6 -3	-4 -2 1	2 3 5	7 8 9	12 14 16	19 21 22	19 20 21	18 20 21	13 15 17	7 8 10	1 3 5	-5 -3 -1
27	-9 -6 -4	-4 -1 2	2 4 6	7 8 9	12 13 15	19 20 22	20 21 22	19 20 21	13 14 16	6 8 9	1 3 5	-3 -1 1
28	-8 -5 -3	-3 -1 1	2 4 6	7 8 10	13 14 15	18 20 21	20 21 22	18 20 21	13 15 16	6 8 10	0 3 5	-4 -2 1
29	-7 -5 -3	-9 -2 5	3 4 6	7 9 11	13 15 16	18 19 21	20 21 22	17 18 20	12 14 16	4 6 8	0 2 5	-3 -2 0
30	-7 -5 -2		4 5 7	8 9 11	14 16 18	19 20 21	20 21 22	18 19 20	11 13 14	5 6 8	-0 2 5	-4 -2 0
31	-7 -4 -2		3 5 7		13 15 17		20 21 22	18 19 21		5 7 10		-5 -3 -1