Yosemite National Park is definitely worth a visit
Vast forests, blue lakes, towering sequoias, and majestic waterfalls hint at the beauty of Yosemite National Park—a true natural masterpiece.
Portsmouth Weather in August
With daytime temperatures of 26°C (79°F) and nighttime lows of 16°C (61°F), August in Portsmouth brings high temperatures during the day. Do keep in mind that quite a bit of rainfall is typical. Around 102 mm (4 in) falls on average.
Rainfall in Portsmouth in August
Expect around 10 days of rain based on historical data, with 102 mm (4 in) average. When showers do arrive, they tend to be on the heavier side. Worth being prepared even if rain days are not that numerous.
Temperature in Portsmouth in August
August in Portsmouth sees highs of 26°C (79°F) and lows of 16°C (61°F) overnight. During August, you'll experience the summer season. Overall, the month follows a fairly predictable daily temperature pattern. At 16°C (61°F) overnight, it can feel quite a bit cooler after dark. Worth packing something warmer for evenings, but the cooler temperatures are ideal for sleeping.
Sunshine in Portsmouth in August
Enjoy a sunny month with about 261 hours of sunshine, the clear skies make Portsmouth even more beautiful.Should you favor a climate that's both dry and comfortably warm, September typically offers the most agreeable circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.
Portsmouth Temperature in August
Min Temperature
16°C (61°F)
Max Temperature
26°C (79°F)
Chance of Rain
33%
Precipitation
102 mm (4 in)
Rainy days
10 days
Humidity
74% *
Sunshine
261 hours *
Percentage Sunshine
*
* Data from: Concord, the United States of America (64 KM, 40 Miles).
Portsmouth Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Portsmouth - and find the best time to visit.
Daily Historical Temperatures
49-year average (1976-2025)
Based on our historical records, temperatures in Portsmouth typically stay consistent throughout August, with daily highs averaging around 26°C (79°F). Nights are pleasant, with lows typically ranging from 14°C (57°F) to 18°C (64°F).
Average temperatures in August
Daily Historical Precipitation
49-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in August
Historical weather records for Portsmouth in August
Browse day-by-day weather records for Portsmouth spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Portsmouth historical weather extremes in August
According to our 29 years of weather records for Portsmouth, the following extremes were recorded between 1997 and 2026.
- The hottest August day on record in Portsmouth reached 37°C (99°F) (August 14, 2002).
- The coldest August day was on August 29, 2009, with a maximum of 16°C (61°F).
- The lowest overnight temperature recorded in August was 6°C (43°F) (August 28, 2025).
- Peak precipitation in August occurred on August 20, 2006, when 61 mm (2.4 in) of precipitation was measured.
Best Places in the United States of America in August
Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in August →
perfect weather
pleasant
tolerable
unpleasant
poor
Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C (68°F) and 29°C (84°F) and not too much precipitation (less than 90 mm (3.5 in) a month).
What to Wear in Portsmouth in August
Warm temperatures in August make for comfortable sightseeing weather. Pack breathable fabrics like cotton shirts, knee-length shorts or skirts, and comfortable walking shoes. A thin long sleeve for indoor spaces is handy. Prepare for significant rainfall with proper waterproof clothing and shoes. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.
What To Do in Portsmouth in August
We rated the following activities from 1 (least suitable) to 10 (best) to do.
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Swimming9/10 -
Cycling7/10 -
Walking7/10 -
Camping6/10 -
Outdoor sports7/10
Portsmouth 3-Day Forecast
More climate data for Portsmouth
Temperature Rainfall Sunshine Humidity
See the full Portsmouth climate overview or explore weather in the United States of America.
Popular in August
Where to go in August - average daytime high across popular destinations.
Kissimmee
33°C (91°F) Orlando33°C (91°F) Miami Beach32°C (90°F) Destin32°C (90°F) New York City
29°C (84°F) Big Bear Lake
27°C (81°F) Los Angeles
24°C (75°F) San Francisco22°C (72°F) Bucket list
Need travel inspiration? Check out our bucket list articles and be inspired.
Yosemite National Park is definitely worth a visit
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