Johnstown weather in May

In May, Johnstown sees average daytime highs of 67°F and overnight lows near 49°F, with 5.0 in of rain across 15.4 wet days and about 14.2 hours of daylight. It is the 5th-warmest and 1st-wettest month of the year here.

Highs climb over the month, from about 63°F in the first days to 70°F by the end. The sky is clear or mostly clear about 21% 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 36 min by month's end. Set against the rest of the year, May is Johnstown's 6th-clearest and 8th-windiest month. For the whole year in context, see Johnstown's year-round climate.

Daytime high
67°
5th warmest
Overnight low
49°
8th coldest
Rainfall
5.0 in
15.4 wet days
Daylight
14 h 12 min
5:05 AM – 7:19 PM
Cloud cover
66%
6th clearest
Wind
7 mph
8th windiest
Solar energy
5.55 kWh/m²
Travel score
5.3
out of 10

Johnstown is city in Cambria County, Pennsylvania, United States.

Density
1,266/km²
people per km²
Founded
1770

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 63°F in the first days to 70°F by the end.

A typical May day in Johnstown reaches about 67°F in the afternoon and slips back to 49°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 54°F and 78°F. Set against its neighbours, May runs about 9°F warmer than April and about 8°F cooler than June.

40°60°80°151015202531
Avg high (°F)Avg low (°F)
16244
26345
36345
46345
56446
66446
76446
86447
96547
106547
116547
126548
136548
146648
156648
166649
176749
186749
196749
206750
216850
226851
236851
246951
256952
266952
277052
287053
297053
307153
317154

How May really feels in Johnstown

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.

Johnstown weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan34° / 20°3.714.410.99.50.0
Feb36° / 21°3.412.49.110.40.0
Mar45° / 29°4.414.16.411.70.9
Apr58° / 39°4.714.62.4133.7
May67° / 49°5.015.4014.25.3
Jun74° / 58°4.814.2014.86.1
Jul78° / 62°4.114.1014.66.2
Aug77° / 60°3.512.3013.66.5
Sep71° / 53°3.910.8012.36.5
Oct59° / 42°3.711.40.810.94.5
Nov47° / 33°3.511.53.59.81.6
Dec38° / 25°3.913.37.69.20.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 21% 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 63%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13664
23664
33763
43763
53763
63664
73763
83763
93763
103763
113664
123664
133664
143565
153664
163565
173565
183565
193565
203565
213664
223763
233763
243763
253862
263961
273961
283961
293961
304060
314060

Chance of precipitation in May

Any precipitation

Johnstown gets around 5.0 in of rain over 15.4 wet days in May, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 50% and peaks near 53% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
151
251
352
452
552
652
752
852
953
1053
1152
1252
1352
1451
1551
1650
1750
1849
1949
2048
2148
2247
2347
2447
2547
2647
2747
2847
2947
3048
3148

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 71% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1871120
2861220
3851320
4841330
5831430
6811540
7811540
8791650
9791650
10781660
11761770
12761770
13751780
14741790
15741790
167317100
177217110
186918121
196918121
206818131
216519142
226419152
236320152
246120163
256020173
265821174
275721184
285721184
295522185
305422195
315422195

Wind in May

Winds average 7 mph in May.

Across May, daily wind ranges from about 6 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
286calm
296calm
306calm
316calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 42 min at the start of May to 14 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 54 minutes over May. Sunrise moves from 5:22 AM to 4:54 AM, and sunset from 7:04 PM to 7:32 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.75:227:04
213.75:217:05
313.85:207:06
413.85:187:07
513.85:177:08
613.95:167:09
713.95:157:10
814.05:137:11
914.05:127:12
1014.05:117:13
1114.15:107:14
1214.15:097:15
1314.15:087:16
1414.25:077:17
1514.25:067:18
1614.25:057:19
1714.35:047:20
1814.35:037:21
1914.35:027:22
2014.45:017:23
2114.45:017:24
2214.45:007:24
2314.44:597:25
2414.54:587:26
2514.54:587:27
2614.54:577:28
2714.54:567:29
2814.64:567:30
2914.64:557:30
3014.64:557:31
3114.64:547:32

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.55 kWh/m².

For context, solar energy here swings from a low near 1.58 kWh/m² to a high of 5.94 kWh/m² in June across the year — May's 5.55 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
75.3Bright
85.3Bright
95.3Bright
105.4Bright
115.4Bright
125.4Bright
135.4Bright
145.4Bright
155.4Bright
165.5Bright
175.5Bright
185.5Bright
195.5Bright
205.6Bright
215.6Bright
225.7Bright
235.7Bright
245.7Bright
255.7Bright
265.8Bright
275.8Bright
285.8Bright
295.8Bright
305.8Bright
315.8Bright
Planning a trip in May

Is May a good time to visit Johnstown?

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

5.3
Sightseeing
5th-best month of the year
2.4
Beach & pool
5th-best month of the year

May is a reasonable time to visit Johnstown for sightseeing.

What to pack for Johnstown in May

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

In May, Johnstown sees daytime highs around 67°F and nights near 49°F. Pack rain gear. Worth having: sun protection. About 15 days see rain.

rain gearsun protection

UV index in Johnstown in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Johnstown peaks around June 23 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJun 23UV 9Dec 19UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug7Very high
Sep6High
Oct3Moderate
Nov2Moderate
Dec2Low

Air quality in Johnstown 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 Johnstown is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (November, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1316 µg/m³Nov 147 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar11Good
Apr12Good
May14Moderate
Jun16Moderate
Jul16Moderate
Aug14Moderate
Sep11Good
Oct8Good
Nov7Good
Dec8Good
Location & terrain

Where is Johnstown?

Johnstown sits at 40.3°N, 78.9°W, 1,168 ft above sea level, in United States. The nearest listed city is Altoona, 30 mi away.

Topography around Johnstown

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

Within 2 miles, the terrain around Johnstown has significant variations in elevation — a maximum elevation change of 837 ft around an average of 1,493 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,831 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,641 ft.

The land around Johnstown is covered by trees (66%) and artificial surfaces (20%) within 2 miles, trees (79%) within 10 miles, and trees (77%) within 50 miles.

2 miles
837 ft
10 miles
1,831 ft
50 miles
2,641 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Altoona 30 mi · Murrysville 42 mi · Plum 45 mi · Monroeville 46 mi · Cumberland 47 mi · McKeesport 50 mi · Penn Hills 50 mi · West Mifflin 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 Johnstown (40.3267°, -78.922°, elevation 1,168 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).