Harrisburg weather in December

In December, Harrisburg sees average daytime highs of 43°F and overnight lows near 30°F, with 3.5 in of precipitation across 9.2 wet days and about 9.2 hours of daylight. It is the 10th-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 46°F in the first days to 40°F by the end. The sky is clear or mostly clear about 22% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 18 min at the start of December to 9 h 12 min by month's end. Set against the rest of the year, December is Harrisburg's 11th-clearest and 5th-windiest month. For the whole year in context, see Harrisburg's year-round climate.

Daytime high
43°
10th warmest
Overnight low
30°
3rd coldest
Precipitation
3.5 in
9.2 wet days
Daylight
9 h 06 min
7:29 AM – 4:38 PM
Cloud cover
67%
11th clearest
Wind
7 mph
5th windiest
Solar energy
1.73 kWh/m²
Travel score
0.4
out of 10

Harrisburg is capital city of the U.S. state of Pennsylvania and seat of Dauphin County.

Density
1,633/km²
people per km²
Founded
1719

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 46°F in the first days to 40°F by the end.

A typical December day in Harrisburg reaches about 43°F in the afternoon and slips back to 30°F overnight — a 12°F spread between the day's warmth and the night's chill. On most days the high lands between 31°F and 55°F. Set against its neighbours, December runs about 10°F cooler than November and about 5°F warmer than January.

20°40°60°151015202531
Avg high (°F)Avg low (°F)
14734
24733
34633
44633
54533
64532
74432
84432
94431
104331
114331
124331
134331
144230
154230
164230
174230
184229
194229
204229
214129
224129
234129
244129
254128
264128
274128
284028
294028
304028
314028

How December really feels in Harrisburg

Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 31 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
31
wind chill below the day's low

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Harrisburg weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan38° / 25°3.394.59.50.0
Feb41° / 26°2.88.94.210.40.2
Mar50° / 33°3.810.63.211.72.3
Apr63° / 44°3.610.60.3135.2
May72° / 53°3.512014.26.3
Jun81° / 63°3.411014.86.1
Jul85° / 68°3.610.3014.65.2
Aug83° / 66°3.19.6013.65.9
Sep76° / 59°4.39012.36.9
Oct64° / 47°3.58.30.110.95.9
Nov53° / 37°3.18.20.79.83.0
Dec43° / 30°3.59.22.99.20.4

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 22% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 15% of December, with mostly cloudy or overcast conditions the remaining 64%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13961
23763
33664
43664
53664
63565
73565
83565
93565
103565
113466
123466
133565
143565
153565
163664
173664
183763
193763
203763
213862
223862
233862
243961
253862
263763
273763
283763
293862
303763
313664

Chance of precipitation in December

Any precipitationSnow

Harrisburg gets around 3.5 in of rain and snow over 9.2 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 30% and peaks near 31% on the wettest days, and about 3 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
1306
2307
3318
4318
5319
6319
73110
83110
93110
103111
113111
123111
133111
143111
153111
163110
173110
183010
193010
20309
21299
22299
23288
24288
25288
26288
27288
28288
29289
30289
312810

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1982
2982
3982
4982
5982
6991
7991
8991
9991
10991
11991
12991
13991
14991
15991
16991
17991
18991
19991
20991
21991
22991
23991
24991
25991
26991
27991
28991
291000
301000
311000

Wind in December

Winds average 7 mph in December.

Across December, daily wind ranges from about 7 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 18 min at the start of December to 9 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 7:17 AM to 7:36 AM, and sunset from 4:38 PM to 4:46 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.37:174:38
29.37:184:37
39.37:194:37
49.37:204:37
59.37:214:37
69.37:224:37
79.27:234:37
89.27:234:37
99.27:244:37
109.27:254:37
119.27:264:37
129.27:274:37
139.27:274:37
149.27:284:38
159.27:294:38
169.17:294:38
179.17:304:38
189.17:314:39
199.17:314:39
209.17:324:39
219.17:324:40
229.17:334:40
239.17:334:41
249.17:344:41
259.17:344:42
269.17:344:42
279.17:354:43
289.17:354:44
299.27:354:44
309.27:354:45
319.27:364:46

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.73 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.73 kWh/m² to a high of 6.06 kWh/m² in June across the year — December's 1.73 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.8Dim
21.8Dim
31.8Dim
41.8Dim
51.8Dim
61.7Dim
71.7Dim
81.7Dim
91.7Dim
101.7Dim
111.7Dim
121.7Dim
131.7Dim
141.7Dim
151.7Dim
161.7Dim
171.7Dim
181.7Dim
191.7Dim
201.7Dim
211.7Dim
221.7Dim
231.7Dim
241.7Dim
251.8Dim
261.8Dim
271.8Dim
281.8Dim
291.8Dim
301.8Dim
311.8Dim
Planning a trip in December

Hazard calendar for Harrisburg

In seasonPeak

None of Harrisburg's seasonal hazards are active in December. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Harrisburg sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit Harrisburg?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

0.4
Sightseeing
10th-best month of the year
0.0
Beach & pool
10th-best month of the year

December is a weaker month for outdoor sightseeing in Harrisburg.

What to pack for Harrisburg in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Harrisburg sees daytime highs around 43°F and nights near 30°F. Pack a warm layer. Worth having: a heavy coat and rain gear. About 9 days see rain.

a warm layera heavy coatrain gear

UV index in Harrisburg in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 1. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Harrisburg peaks around June 22 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJun 22UV 8Dec 21UV 1
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul8Very high
Aug6High
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low

Air quality in Harrisburg in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Harrisburg is worst in July — around 17 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (November, 8 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1316 µg/m³Nov 118 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar12Moderate
Apr13Moderate
May14Moderate
Jun16Moderate
Jul17Moderate
Aug14Moderate
Sep11Good
Oct8Good
Nov8Good
Dec9Good
Location & terrain

Where is Harrisburg?

Harrisburg sits at 40.3°N, 76.9°W, 331 ft above sea level, in United States. The nearest listed city is Carlisle, 17 mi away.

Topography around Harrisburg

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Harrisburg.

Within 2 miles, the terrain around Harrisburg has only modest variations in elevation — a maximum elevation change of 335 ft around an average of 367 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,260 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,300 ft.

The land around Harrisburg is covered by artificial surfaces (39%), trees (32%) and water (21%) within 2 miles, trees (59%) within 10 miles, and trees (58%) and cropland (22%) within 50 miles.

2 miles
335 ft
10 miles
1,260 ft
50 miles
2,300 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Carlisle 17 mi · York 23 mi · Lebanon 25 mi · Hanover 33 mi · Lancaster 35 mi · Chambersburg 47 mi · Westminster 48 mi · Reading 50 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Harrisburg (40.2737°, -76.8844°, elevation 331 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).