Portsmouth weather in May

In May, Portsmouth sees average daytime highs of 74°F and overnight lows near 56°F, with 4.6 in of rain across 12.9 wet days and about 14.1 hours of daylight. It is the 5th-warmest and 1st-wettest month of the year here.

Highs climb over the month, from about 70°F in the first days to 77°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 36 min at the start of May to 14 h 30 min by month's end. Set against the rest of the year, May is Portsmouth's 8th-clearest and 8th-windiest month. For the whole year in context, see Portsmouth's year-round climate.

Daytime high
74°
5th warmest
Overnight low
56°
8th coldest
Rainfall
4.6 in
12.9 wet days
Daylight
14 h 06 min
5:25 AM – 7:31 PM
Cloud cover
64%
8th clearest
Wind
6 mph
8th windiest
Solar energy
5.68 kWh/m²
Travel score
6.2
out of 10

Portsmouth is city in Scioto County, Ohio, United States.

Density
712/km²
people per km²
Founded
1803

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 70°F in the first days to 77°F by the end.

A typical May day in Portsmouth reaches about 74°F in the afternoon and slips back to 56°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 62°F and 85°F. Set against its neighbours, May runs about 8°F warmer than April and about 8°F cooler than June.

40°60°80°151015202531
Avg high (°F)Avg low (°F)
17051
27051
37052
47152
57152
67153
77153
87253
97254
107254
117254
127355
137355
147355
157355
167356
177456
187456
197456
207557
217557
227557
237658
247658
257658
267759
277759
287760
297860
307860
317860

How May really feels in Portsmouth

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.

Portsmouth 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
Jan41° / 27°3.410.23.69.60.1
Feb45° / 29°3.410.13.710.50.8
Mar54° / 36°4.2121.711.73.1
Apr66° / 47°4.412.40.3135.6
May74° / 56°4.612.9014.16.2
Jun82° / 64°4.313.1014.75.6
Jul85° / 68°3.912.5014.44.9
Aug85° / 66°3.011.2013.55.3
Sep79° / 59°3.38.1012.37.0
Oct67° / 48°3.190.1116.3
Nov54° / 38°3.28.70.69.93.5
Dec45° / 31°3.6102.39.30.9

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 19% of May, with mostly cloudy or overcast conditions the remaining 59%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13862
23763
33763
43763
53862
63862
73763
83862
93862
103961
113961
124060
134060
144060
154159
164159
174258
184258
194258
204258
214258
224258
234357
244456
254456
264456
274555
284654
294654
304654
314654

Chance of precipitation in May

Any precipitation

Portsmouth gets around 4.6 in of rain over 12.9 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 42% and peaks near 44% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
144
244
344
443
543
643
743
843
943
1043
1143
1243
1343
1443
1542
1642
1742
1842
1942
2042
2142
2241
2341
2441
2541
2640
2740
2840
2940
3040
3140

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 48% of days. Sticky, muggy-or-worse air turns up on roughly 14% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
17019920
268191120
366201220
464201330
562201440
662201440
759211550
857211660
956211670
1054211780
1154201790
12532017100
13512018110
14502018120
15492018120
16481919130
17471919140
18461919150
19451920160
20441820171
21421820181
22411821191
23391921201
24381922201
25361922211
26351922222
27341923222
28331923232
29321923232
30311924242
31301924252

Wind in May

Winds average 6 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
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 36 min at the start of May to 14 h 30 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 5:41 AM to 5:15 AM, and sunset from 7:17 PM to 7:44 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.65:417:17
213.65:407:18
313.75:397:19
413.75:387:20
513.75:367:21
613.85:357:22
713.85:347:23
813.85:337:24
913.95:327:25
1013.95:317:26
1113.95:307:27
1214.05:297:28
1314.05:287:29
1414.05:277:29
1514.15:267:30
1614.15:257:31
1714.15:247:32
1814.25:237:33
1914.25:237:34
2014.25:227:35
2114.25:217:36
2214.35:207:37
2314.35:207:38
2414.35:197:38
2514.35:187:39
2614.45:187:40
2714.45:177:41
2814.45:167:42
2914.45:167:42
3014.55:157:43
3114.55:157:44

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.68 kWh/m².

For context, solar energy here swings from a low near 1.73 kWh/m² to a high of 6.11 kWh/m² in June across the year — May's 5.68 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.3Bright
35.3Bright
45.4Bright
55.4Bright
65.4Bright
75.4Bright
85.5Bright
95.5Bright
105.5Bright
115.5Bright
125.5Bright
135.6Bright
145.6Bright
155.6Bright
165.7Bright
175.7Bright
185.7Bright
195.8Bright
205.8Bright
215.8Bright
225.8Bright
235.9Bright
245.9Bright
255.9Bright
265.9Bright
276.0Bright
286.0Bright
296.0Bright
306.0Bright
316.0Bright
Planning a trip in May

Hazard calendar for Portsmouth

In seasonPeak

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

Portsmouth 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 May a good time to visit Portsmouth?

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

6.2
Sightseeing
3rd-best month of the year
4.9
Beach & pool
5th-best month of the year

May is a reasonable time to visit Portsmouth for sightseeing.

What to pack for Portsmouth in May

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

In May, Portsmouth sees daytime highs around 74°F and nights near 56°F. Worth packing: light clothes, rain gear and sun protection. About 13 days see rain.

light clothesrain gearsun protection

UV index in Portsmouth 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 Portsmouth peaks around June 18 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateJun 18UV 9Jan 1UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov3Moderate
Dec2Low

Air quality in Portsmouth 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 Portsmouth is worst in July — around 18 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (October, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1218 µg/m³Oct 248 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb10Good
Mar10Good
Apr11Good
May14Moderate
Jun17Moderate
Jul18Moderate
Aug15Moderate
Sep12Good
Oct8Good
Nov8Good
Dec8Good
Location & terrain

Where is Portsmouth?

Portsmouth sits at 38.7°N, 83.0°W, 531 ft above sea level, in United States. The nearest listed city is Ashland, 26 mi away.

Topography around Portsmouth

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

Within 2 miles, the terrain around Portsmouth has only modest variations in elevation — a maximum elevation change of 640 ft around an average of 620 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 817 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 925 ft.

The land around Portsmouth is covered by trees (42%) within 2 miles, trees (77%) within 10 miles, and trees (77%) within 50 miles.

2 miles
640 ft
10 miles
817 ft
50 miles
925 ft
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Ashland 26 mi · Meads 27 mi · Huntington 37 mi · Chillicothe 42 mi · Athens 63 mi · Lancaster 71 mi · Charleston 78 mi · Grove City 80 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 Portsmouth (38.7317°, -82.9977°, elevation 531 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).