Williamsport weather in May

In May, Williamsport sees average daytime highs of 68°F and overnight lows near 49°F, with 4.0 in of rain across 13.2 wet days and about 14.3 hours of daylight. It is the 5th-warmest and 4th-wettest month of the year here.

Highs climb over the month, from about 65°F in the first days to 73°F by the end. The sky is clear or mostly clear about 22% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 42 min at the start of May to 14 h 42 min by month's end. Set against the rest of the year, May is Williamsport's 6th-clearest and 8th-windiest month. For the whole year in context, see Williamsport's year-round climate.

Daytime high
68°
5th warmest
Overnight low
49°
8th coldest
Rainfall
4.0 in
13.2 wet days
Daylight
14 h 18 min
4:55 AM – 7:13 PM
Cloud cover
66%
6th clearest
Wind
6 mph
8th windiest
Solar energy
5.57 kWh/m²
Travel score
5.8
out of 10

Williamsport is city in and county seat of Lycoming County, Pennsylvania, United States.

Density
1,196/km²
people per km²
Founded
1769

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 65°F in the first days to 73°F by the end.

A typical May day in Williamsport reaches about 68°F in the afternoon and slips back to 49°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 57°F and 81°F. Set against its neighbours, May runs about 10°F warmer than April and about 9°F cooler than June.

40°60°80°151015202531
Avg high (°F)Avg low (°F)
16445
26445
36545
46546
56546
66546
76647
86647
96647
106647
116748
126748
136748
146749
156849
166849
176849
186950
196950
206950
217051
227051
237151
247152
257152
267253
277253
287253
297354
307354
317354

How May really feels in Williamsport

Once humidity and wind are folded in, May averages 0 days that feel above 90°F and 0 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
0
wind chill below the day's low

May sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Williamsport weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan33° / 20°3.210.16.39.40.0
Feb36° / 21°2.79.15.610.30.0
Mar46° / 29°3.9114.411.71.1
Apr58° / 40°4.111.81.213.14.1
May68° / 49°4.013.2014.35.8
Jun77° / 58°4.211.9014.96.4
Jul81° / 63°3.711.5014.76.2
Aug80° / 62°3.710.5013.76.5
Sep72° / 54°4.69.5012.36.8
Oct60° / 43°3.9100.310.94.9
Nov48° / 34°3.591.49.71.8
Dec38° / 26°3.510.14.69.10.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

Beyond those clear spells, partly cloudy skies cover about 16% of May, with mostly cloudy or overcast conditions the remaining 61%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13862
23862
33763
43763
53763
63763
73763
83763
93664
103664
113664
123664
133664
143763
153763
163763
173664
183664
193763
203862
213862
223961
234060
244159
254258
264357
274258
284357
294456
304357
314357

Chance of precipitation in May

Any precipitation

Williamsport gets around 4.0 in of rain over 13.2 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 42% and peaks near 43% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
141
241
341
442
542
642
742
842
942
1042
1142
1242
1342
1442
1542
1642
1743
1843
1943
2043
2142
2242
2342
2442
2542
2642
2742
2842
2942
3041
3141

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the dry band about 75% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
190820
290820
389920
488930
5871030
6861040
7851140
8841150
9841150
10831250
11821260
12821260
13811270
14801370
15791380
16761491
17761491
187415101
197315111
207016122
216916132
226716143
236617143
246417154
256317164
266018175
276018175
285918185
295818186
305718196
315618197

Wind in May

Winds average 6 mph in May.

Across May, daily wind ranges from about 5 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 42 min at the start of May to 14 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 60 minutes over May. Sunrise moves from 5:13 AM to 4:44 AM, and sunset from 6:58 PM to 7:27 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.75:136:58
213.85:116:59
313.85:107:00
413.95:097:01
513.95:087:02
613.95:067:03
714.05:057:04
814.05:047:05
914.15:037:06
1014.15:027:07
1114.15:007:08
1214.24:597:09
1314.24:587:10
1414.24:577:11
1514.34:567:12
1614.34:557:13
1714.34:547:14
1814.44:537:15
1914.44:527:16
2014.44:517:17
2114.54:517:18
2214.54:507:19
2314.54:497:20
2414.54:487:21
2514.64:477:22
2614.64:477:23
2714.64:467:24
2814.74:457:25
2914.74:457:25
3014.74:447:26
3114.74:447:27

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.57 kWh/m².

For context, solar energy here swings from a low near 1.56 kWh/m² to a high of 5.98 kWh/m² in June across the year — May's 5.57 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.3Bright
35.3Bright
45.3Bright
55.3Bright
65.3Bright
75.4Bright
85.4Bright
95.4Bright
105.4Bright
115.4Bright
125.4Bright
135.5Bright
145.5Bright
155.5Bright
165.5Bright
175.5Bright
185.6Bright
195.6Bright
205.6Bright
215.7Bright
225.7Bright
235.7Bright
245.7Bright
255.8Bright
265.8Bright
275.8Bright
285.8Bright
295.8Bright
305.8Bright
315.8Bright
Planning a trip in May

Is May a good time to visit Williamsport?

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

5.8
Sightseeing
5th-best month of the year
3.2
Beach & pool
5th-best month of the year

May is a reasonable time to visit Williamsport for sightseeing.

What to pack for Williamsport in May

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

In May, Williamsport sees daytime highs around 68°F and nights near 49°F. Worth packing: rain gear and sun protection. About 13 days see rain.

rain gearsun protection

UV index in Williamsport in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Williamsport peaks around June 23 at about 9 (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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 23UV 9Dec 21UV 1
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug6High
Sep6High
Oct3Moderate
Nov2Moderate
Dec1Low

Air quality in Williamsport in May

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Williamsport is worst in July — around 15 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (November, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1415 µg/m³Nov 127 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb10Good
Mar11Good
Apr11Good
May13Moderate
Jun14Moderate
Jul15Moderate
Aug13Moderate
Sep11Good
Oct7Good
Nov7Good
Dec8Good
Location & terrain

Where is Williamsport?

Williamsport sits at 41.2°N, 77.0°W, 518 ft above sea level, in United States. The nearest listed city is Back Mountain, 53 mi away.

Topography around Williamsport

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

Within 2 miles, the terrain around Williamsport has significant variations in elevation — a maximum elevation change of 1,148 ft around an average of 686 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,585 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,228 ft.

The land around Williamsport is covered by trees (48%) and artificial surfaces (29%) within 2 miles, trees (68%) within 10 miles, and trees (79%) within 50 miles.

2 miles
1,148 ft
10 miles
1,585 ft
50 miles
2,228 ft
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Back Mountain 53 mi · State College 55 mi · Hazleton 57 mi · Wilkes-Barre 58 mi · Elmira 60 mi · Harrisburg 67 mi · Lebanon 70 mi · Scranton 70 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 Williamsport (41.2412°, -77.0011°, elevation 518 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. 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).