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CheckWeather USPortsmouth
Forecast confidence: High · models disagree by 2°F

Portsmouth weather

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Showers,rain likely tomorrow

NWS, the American and the European model agree on a high near 87° in Portsmouth today. Tomorrow looks rain around 82°, with a 15% chance of rain.

87°73°
82°72°
81°69°
83°67°
88°67°
93°71°
Todaymodels agreeTomorrowmodels agreeMondaymodels agreeTuesdaymodels agreeWednesdaymodels agreeThursdaymodels agree
NWSNational Blend (NBM)
88°
Showers
Today 88°·Low 75°·Rain 39%
AmericanNOAA GFS
88°
Cloudy
Today 88°·Low 73°·Rain 39%
EuropeanECMWF
86°
Showers
Today 86°·Low 72°·Rain 100%

The weather map: all three models at once

NWS, American, European side by side around Portsmouth and nearby towns.Live rain radar →
Loading the three model maps…

Next 14 hours

consensus of the three models

14-day forecast

where the models agree, and where they split
Today
Showers
87° 73°
models agree
Tomorrow
Rain
82° 72°
models agree
Mon
Drizzle
81° 69°
models agree
Tue
Cloudy
83° 67°
models agree
Wed
Cloudy
88° 67°
models agree
Thu
Mostly clear
93° 71°
models agree
Fri
Mostly clear
86° 73°
±6°
Sat
Light drizzle
88° 71°
±10°
Sun
Mostly clear
90° 72°
±10°
Mon
Light drizzle
92° 75°
±12°
Tue
Drizzle
85° 72°
±20°
Wed
Thunderstorm
84° 69°
±16°
Thu
Thunderstorm
75° 69°
models agree
Fri
Heavy drizzle
75° 67°
±4°

Portsmouth, VA is at its warmest in Jul (average highs near 87°F) and coldest in Jan (lows around 38°F), with roughly 47 in of precipitation across the year. Below, compare what NWS, American, European forecast for Portsmouth right now, and see exactly where they disagree.

We grade every model against the weather that actually happened, so you can see which forecast model is most accurate in United States before you trust any single number.

Portsmouth climate by month

average daytime high and overnight low across a typical year
Jan
55°
38°
Feb
57°
40°
Mar
61°
43°
Apr
71°
52°
May
74°
59°
Jun
83°
65°
Jul
87°
72°
Aug
85°
70°
Sep
79°
66°
Oct
71°
54°
Nov
62°
46°
Dec
54°
39°

Which forecast is most accurate in Portsmouth?

CheckWeather Score — graded against the weather that actually happened
ProviderCheckWeather Score🌡 Temp💨 Wind🌧 RainRun by
European logo
European ★ Best
89
/100rank #1
94±0.6°F98±0.7 mph7687% hitECMWF - European Centre for Medium-Range Weather ForecastsReading, United Kingdom
American logo
American
61
/100rank #2
73±2.7°F93±2.0 mph2458% hitNOAA / NCEP (United States)College Park, Maryland, USA

The CheckWeather Score blends temperature, wind and rain accuracy — each measured against ERA5 (the recorded weather) over the last 30 days across 1999 cities. Lower error means a higher score. See which forecast model is most accurate in United States, how we measure forecast accuracy, or which model each weather app uses.

Where the models disagree

temperature and rain, judged separately
DayTemperatureRain
Today±2°86° to 88°±61%39% to 100% chance
Tomorrow±1°82° to 83°±4%11% to 15% chance
Mon±3°80° to 82°±17%4% to 21% chance
Tue±2°82° to 84°±2%0% to 2% chance
Wed±3°87° to 90°±15%1% to 16% chance

The models often agree on temperature and still split on rain — and rain is usually what decides whether a plan survives. A wide rain range means the shower is genuinely uncertain, not that the forecast is wrong.

Sunrise and sunset in Portsmouth

today, local time
Sunrise
06:39
Sunset
19:28
Daylight
12h 49m

Common questions

What's the weather in Portsmouth today?
On this page we show what NWS, American, European each forecast for Portsmouth today, side by side and updated live. When all three agree the forecast is reliable; when they split, we flag it so you know the day is genuinely less certain.
Will it rain in Portsmouth today or tomorrow?
Check the hourly strip and 7-day forecast above. We compare rain from NWS, American, European for Portsmouth and flag the days where the models disagree on whether showers actually arrive, which is exactly when a single app can catch you out.
Which forecast is most accurate for Portsmouth?
Over the last 30 days, the European model has been the most accurate for Portsmouth (CheckWeather Score 89/100), ahead of the American at 61. We grade every model against the recorded weather. See the US accuracy scoreboard for the full method.
What is the warmest month in Portsmouth?
July is typically the warmest month in Portsmouth, with average highs around 87°F.
How cold does Portsmouth get?
The coldest month in Portsmouth is January, when overnight lows average about 38°F.
How much rain does Portsmouth get?
Portsmouth sees roughly 47 in of precipitation a year, with June usually the wettest month.

Nearby

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