Portsmouth in Summer
In summer (June, July and August), Portsmouth sees average daytime highs around 84°F and overnight lows near 66°F, with 11.3 in of rain over about 37 wet days across the season. It is the warmest season of the year and the 2nd-wettest season.
Over the season highs climb from about 79°F in early June to 84°F by late August. The sky is clear or mostly clear about 31% of the time across summer, and the air most often feels muggy.
Summer is Portsmouth's 2nd-best season to visit on our travel score. For the whole year in context, see Portsmouth's year-round climate.
- Avg daytime high
- 84°F
- warmest season of the year
- Avg overnight low
- 66°F
- Rainfall
- 11.3 in
- 37 wet days
- Avg wind
- 5 mph
- Travel score
- 5.3
- 2nd-best season
- Months
- Jun · Jul · Aug
Temperature in Portsmouth in Summer
Over the season highs climb from about 79°F in early June to 84°F by late August.
A typical summer day in Portsmouth reaches about 84°F and drops to 66°F overnight. The warmest of the three months is July, the coolest June.
How summer really feels in Portsmouth
Once humidity and wind are folded in, summer brings about 0 days that feel above 90°F and 0 that feel at or below 32°F.
summer 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 the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 41° / 27° | 3.4 | 10.2 | 3.6 | 9.6 | 0.1 |
| Feb | 45° / 29° | 3.4 | 10.1 | 3.7 | 10.5 | 0.8 |
| Mar | 54° / 36° | 4.2 | 12 | 1.7 | 11.7 | 3.1 |
| Apr | 66° / 47° | 4.4 | 12.4 | 0.3 | 13 | 5.6 |
| May | 74° / 56° | 4.6 | 12.9 | 0 | 14.1 | 6.2 |
| Jun | 82° / 64° | 4.3 | 13.1 | 0 | 14.7 | 5.6 |
| Jul | 85° / 68° | 3.9 | 12.5 | 0 | 14.4 | 4.9 |
| Aug | 85° / 66° | 3.0 | 11.2 | 0 | 13.5 | 5.3 |
| Sep | 79° / 59° | 3.3 | 8.1 | 0 | 12.3 | 7.0 |
| Oct | 67° / 48° | 3.1 | 9 | 0.1 | 11 | 6.3 |
| Nov | 54° / 38° | 3.2 | 8.7 | 0.6 | 9.9 | 3.5 |
| Dec | 45° / 31° | 3.6 | 10 | 2.3 | 9.3 | 0.9 |
Cloud cover in Summer
The sky is clear or mostly clear about 31% of the time across summer.
Chance of precipitation in Summer
Portsmouth gets around 11.3 in of rain over 37 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 5 mph across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 30 min in early June to 12 h 54 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 5.9 kWh/m².
Hazard calendar for Portsmouth
In summer, Portsmouth overlaps its atlantic hurricane season. The full year is below, with each hazard's peak months called out.
Portsmouth sits in the Atlantic hurricane belt; the season peaks August–October.
Is summer a good time to visit Portsmouth?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit Portsmouth for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Portsmouth in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Portsmouth sees daytime highs around 84°F and nights near 66°F. Pack light clothes and sun protection. Worth having: rain gear. About 37 days see rain.
UV index in Portsmouth in Summer
Clear-sky midday UV across summer averages around 9 (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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 3 | 5 | 6 | 8 | 9 | 9 | 8 | 6 | 3 | 3 | 2 |
| Level | Low | Moderate | Moderate | High | Very high | Very high | Very high | Very high | High | Moderate | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 3 | Moderate |
| Mar | 5 | Moderate |
| Apr | 6 | High |
| May | 8 | Very high |
| Jun | 9 | Very high |
| Jul | 9 | Very high |
| Aug | 8 | Very high |
| Sep | 6 | High |
| Oct | 3 | Moderate |
| Nov | 3 | Moderate |
| Dec | 2 | Low |
Air quality in Portsmouth in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer 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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 9 | 10 | 10 | 11 | 14 | 17 | 18 | 15 | 12 | 8 | 8 | 8 |
| Level | Good | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 9 | Good |
| Feb | 10 | Good |
| Mar | 10 | Good |
| Apr | 11 | Good |
| May | 14 | Moderate |
| Jun | 17 | Moderate |
| Jul | 18 | Moderate |
| Aug | 15 | Moderate |
| Sep | 12 | Good |
| Oct | 8 | Good |
| Nov | 8 | Good |
| Dec | 8 | Good |
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.
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
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.