| Climate data for Duluth Int'l, Minnesota (1991–2020 normals,[a] extremes 1871–present[b]) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Record high °F (°C) | 55 (13) |
58 (14) |
81 (27) |
88 (31) |
95 (35) |
97 (36) |
106 (41) |
97 (36) |
97 (36) |
86 (30) |
75 (24) |
56 (13) |
106 (41) |
| Mean maximum °F (°C) | 38.6 (3.7) |
43.0 (6.1) |
55.9 (13.3) |
70.7 (21.5) |
81.7 (27.6) |
86.0 (30.0) |
88.6 (31.4) |
86.7 (30.4) |
81.9 (27.7) |
74.0 (23.3) |
55.4 (13.0) |
40.3 (4.6) |
90.2 (32.3) |
| Mean daily maximum °F (°C) | 19.9 (−6.7) |
24.8 (−4.0) |
36.2 (2.3) |
49.2 (9.6) |
63.0 (17.2) |
72.1 (22.3) |
77.7 (25.4) |
75.8 (24.3) |
67.2 (19.6) |
52.7 (11.5) |
37.1 (2.8) |
24.7 (−4.1) |
50.0 (10.0) |
| Daily mean °F (°C) | 11.2 (−11.6) |
15.4 (−9.2) |
27.0 (−2.8) |
39.5 (4.2) |
52.0 (11.1) |
61.2 (16.2) |
67.0 (19.4) |
65.5 (18.6) |
57.2 (14.0) |
44.1 (6.7) |
29.8 (−1.2) |
17.1 (−8.3) |
40.6 (4.8) |
| Mean daily minimum °F (°C) | 2.4 (−16.4) |
6.0 (−14.4) |
17.8 (−7.9) |
29.9 (−1.2) |
41.0 (5.0) |
50.2 (10.1) |
56.2 (13.4) |
55.2 (12.9) |
47.3 (8.5) |
35.6 (2.0) |
22.5 (−5.3) |
9.6 (−12.4) |
31.1 (−0.5) |
| Mean minimum °F (°C) | −21.9 (−29.9) |
−17.3 (−27.4) |
−7.4 (−21.9) |
14.7 (−9.6) |
28.7 (−1.8) |
38.1 (3.4) |
45.7 (7.6) |
44.6 (7.0) |
32.5 (0.3) |
21.9 (−5.6) |
2.7 (−16.3) |
−14.3 (−25.7) |
−23.9 (−31.1) |
| Record low °F (°C) | −41 (−41) |
−39 (−39) |
−29 (−34) |
−5 (−21) |
16 (−9) |
27 (−3) |
35 (2) |
32 (0) |
23 (−5) |
6 (−14) |
−29 (−34) |
−35 (−37) |
−41 (−41) |
| Average precipitation inches (mm) | 0.95 (24) |
1.01 (26) |
1.46 (37) |
2.53 (64) |
3.37 (86) |
4.39 (112) |
3.92 (100) |
3.73 (95) |
3.48 (88) |
2.91 (74) |
1.96 (50) |
1.47 (37) |
31.18 (792) |
| Average snowfall inches (cm) | 16.8 (43) |
15.1 (38) |
12.8 (33) |
9.1 (23) |
0.8 (2.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.1 (0.25) |
2.7 (6.9) |
14.1 (36) |
18.7 (47) |
90.2 (229) |
| Average extreme snow depth inches (cm) | 18.6 (47) |
20.3 (52) |
19.4 (49) |
8.2 (21) |
0.4 (1.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
1.2 (3.0) |
6.6 (17) |
12.7 (32) |
24.8 (63) |
| Average precipitation days (≥ 0.01 in) | 10.4 | 8.9 | 9.6 | 11.3 | 12.7 | 12.4 | 11.9 | 10.8 | 11.6 | 11.9 | 11.0 | 10.7 | 133.2 |
| Average snowy days (≥ 0.1 in) | 13.1 | 10.9 | 8.0 | 5.7 | 0.6 | 0.0 | 0.0 | 0.0 | 0.1 | 2.1 | 9.0 | 12.9 | 62.4 |
| Average relative humidity (%) | 72.0 | 69.8 | 69.3 | 63.6 | 62.7 | 69.5 | 70.9 | 74.5 | 75.7 | 71.4 | 74.9 | 76.3 | 70.9 |
| Average dew point °F (°C) | 0.3 (−17.6) |
4.5 (−15.3) |
15.4 (−9.2) |
25.5 (−3.6) |
36.5 (2.5) |
48.2 (9.0) |
55.0 (12.8) |
54.0 (12.2) |
45.7 (7.6) |
34.0 (1.1) |
21.2 (−6.0) |
7.2 (−13.8) |
29.0 (−1.7) |
| Mean monthly sunshine hours | 132.7 | 149.7 | 190.7 | 229.5 | 263.5 | 272.8 | 307.5 | 261.8 | 194.0 | 150.4 | 98.5 | 102.3 | 2,353.4 |
| Percent possible sunshine | 47 | 52 | 52 | 56 | 57 | 58 | 64 | 60 | 51 | 44 | 35 | 38 | 53 |
| Source: NOAA (relative humidity, dew point, and sun 1961–1990)[1][2][3] | |||||||||||||
- ^ Mean monthly maxima and minima (i.e. the expected highest and lowest temperature readings at any point during the year or given month) calculated based on data at said location from 1991 to 2020.
- ^ Official records for Duluth were kept at downtown from August 1871 to May 1941, and at Duluth Int'l since June 1941. For more information, see ThreadEx.
- ^ "NowData – NOAA Online Weather Data". National Oceanic and Atmospheric Administration. Retrieved June 22, 2021.
- ^ "Station: Duluth, MN". U.S. Climate Normals 2020: U.S. Monthly Climate Normals (1991–2020). National Oceanic and Atmospheric Administration. Retrieved June 22, 2021.
- ^ "WMO Climate Normals for DULUTH/WSO AP MN 1961–1990". National Oceanic and Atmospheric Administration. Retrieved June 22, 2021.