| Climate data for Harrisburg, Pennsylvania ( Harrisburg Int'l), 1991–2020 normals, [a] extremes 1888–present [b] | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Record high °F (°C) | 73 (23) |
79 (26) |
87 (31) |
93 (34) |
97 (36) |
100 (38) |
107 (42) |
104 (40) |
102 (39) |
97 (36) |
84 (29) |
75 (24) |
107 (42) |
| Mean maximum °F (°C) | 59.3 (15.2) |
61.4 (16.3) |
72.7 (22.6) |
83.5 (28.6) |
89.5 (31.9) |
93.3 (34.1) |
96.2 (35.7) |
93.8 (34.3) |
89.7 (32.1) |
81.1 (27.3) |
70.8 (21.6) |
62.3 (16.8) |
97.0 (36.1) |
| Mean daily maximum °F (°C) | 38.6 (3.7) |
42.0 (5.6) |
51.3 (10.7) |
63.8 (17.7) |
73.7 (23.2) |
82.4 (28.0) |
86.8 (30.4) |
84.7 (29.3) |
77.6 (25.3) |
65.7 (18.7) |
53.9 (12.2) |
43.3 (6.3) |
63.6 (17.6) |
| Daily mean °F (°C) | 30.8 (−0.7) |
33.4 (0.8) |
41.8 (5.4) |
53.2 (11.8) |
63.4 (17.4) |
72.5 (22.5) |
77.3 (25.2) |
75.2 (24.0) |
67.9 (19.9) |
55.8 (13.2) |
44.8 (7.1) |
35.8 (2.1) |
54.3 (12.4) |
| Mean daily minimum °F (°C) | 23.0 (−5.0) |
24.7 (−4.1) |
32.3 (0.2) |
42.5 (5.8) |
53.1 (11.7) |
62.7 (17.1) |
67.8 (19.9) |
65.8 (18.8) |
58.2 (14.6) |
46.0 (7.8) |
35.8 (2.1) |
28.2 (−2.1) |
45.0 (7.2) |
| Mean minimum °F (°C) | 7.4 (−13.7) |
10.1 (−12.2) |
17.9 (−7.8) |
29.2 (−1.6) |
39.6 (4.2) |
50.8 (10.4) |
58.3 (14.6) |
55.8 (13.2) |
45.2 (7.3) |
33.0 (0.6) |
22.9 (−5.1) |
14.6 (−9.7) |
5.0 (−15.0) |
| Record low °F (°C) | −22 (−30) |
−13 (−25) |
−1 (−18) |
11 (−12) |
30 (−1) |
40 (4) |
49 (9) |
45 (7) |
30 (−1) |
23 (−5) |
10 (−12) |
−8 (−22) |
−22 (−30) |
| Average precipitation inches (mm) | 3.03 (77) |
2.59 (66) |
3.70 (94) |
3.55 (90) |
3.83 (97) |
3.98 (101) |
4.74 (120) |
3.77 (96) |
4.83 (123) |
3.81 (97) |
2.97 (75) |
3.43 (87) |
44.23 (1,123) |
| Average snowfall inches (cm) | 9.1 (23) |
9.4 (24) |
5.6 (14) |
0.4 (1.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.0 (0.0) |
0.2 (0.51) |
0.8 (2.0) |
4.4 (11) |
29.9 (76) |
| Average precipitation days (≥ 0.01 in) | 10.9 | 10.4 | 11.0 | 11.4 | 13.0 | 11.5 | 10.9 | 10.0 | 9.2 | 9.2 | 8.5 | 10.3 | 126.3 |
| Average snowy days (≥ 0.1 in) | 5.1 | 4.8 | 2.7 | 0.3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.7 | 2.7 | 16.3 |
| Average ultraviolet index | 2 | 3 | 4 | 6 | 8 | 9 | 9 | 8 | 6 | 4 | 2 | 2 | 5 |
| Source 1: NOAA [2] [3] | |||||||||||||
| Source 2: Weather Atlas (UV data) [4] | |||||||||||||
- ^ Mean monthly maxima and minima (i.e. the highest and lowest temperature readings during an entire month or year) calculated based on data at said location from 1981 to 2010.
- ^ Official records for Harrisburg kept at downtown from July 1888 to December 1938, Capital City Airport from January 1939 to September 1991, and at Harrisburg Int'l in Middletown since October 1991. [1]
- ^ ThreadEx
- ^ "NowData – NOAA Online Weather Data". National Oceanic and Atmospheric Administration. Retrieved August 7, 2021.
- ^ "Station: Middletown Harrisburg INTL AP, PA". U.S. Climate Normals 2020: U.S. Monthly Climate Normals (1991–2020). National Oceanic and Atmospheric Administration. Retrieved August 7, 2021.
- ^ "Harrisburg, Pennsylvania, USA - Monthly weather forecast and Climate data". Weather Atlas. Retrieved July 4, 2019.