Portsmouth Temperature by Month
Portsmouth in Virginia, United States of America sees significant seasonal temperature differences, with daytime highs between 10°C (50°F) in February and 32°C (90°F) in July, averaging 21°C (70°F) annually. Explore the full monthly breakdown below.
Portsmouth Monthly Temperatures
The climate in Portsmouth is dynamic, ranging widely from chilly in winter to very warm in summer. Nights are significantly colder, with lows dropping from 22°C (72°F) in July to 0°C (32°F) in February.
The chart below illustrates the average maximum day and minimum night temperatures in Portsmouth by month:
Low temperatures are most often recorded between 4 AM and 6 AM, while highs typically occur around 3 PM. July, the city's warmest month, sees 279 hours of sunshine.
The chart below shows the average temperature throughout the year:
Temperature: Portsmouth vs the United States of America
The map below shows the annual temperature across the United States of America. You can also select individual months if you want to compare a specific time of year.
very warm
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Portsmouth vs World: Temperature Compared
Portsmouth's average annual maximum temperature is 21°C (70°F). To put that in context, here's how it compares to a few well-known destinations:
Rome, Italy averages 20°C (68°F) annually, with reliably warm summers and comfortable winters.
Interlaken, Switzerland averages 8°C (46°F) a year, with cold winters and cool summers thanks to its Alpine setting.
Shanghai, China averages 21°C (70°F) a year, with warm summers, mild winters, and a noticeable spring and autumn.
Tokyo, Japan averages 21°C (70°F) a year, with hot summers, cool winters, and a well-defined cherry blossom spring.
What Does the Temperature Feel Like in Portsmouth?
Temperature alone doesn't tell the whole story — humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.
In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.
In Portsmouth, February is the coolest month, with average highs of 11°C (52°F) and humidity around 65% — considered high. In July, the warmest month, temperatures average 32°C (90°F) with 72% humidity — conditions that feel high. For a full picture, see our humidity page.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
Whether a city sits on the coast or deep inland makes a significant difference to its climate. Coastal areas tend to have more stable temperatures year-round — large bodies of water absorb heat slowly in summer and release it gradually in winter, keeping extremes in check. Cities far from the sea don't benefit from that buffer, which is why continental climates tend to have hotter summers and colder winters than their coastal counterparts at the same latitude.
For more on Portsmouth's weather — including monthly rainfall, sunshine hours, and humidity — visit our Portsmouth climate page.
