The best times to visit Portsmouth for ideal weather are
May 28th to October 7th
Portsmouth Travel Guide
Other Portsmouth Travel Info
Weather in Portsmouth
Average temperatures in Portsmouth vary somewhat. Considering humidity, temperatures feel cold for about half of the year and otherwise nice with a chance of rain or snow throughout most of the year. The area is less temperate than some — in the 30th percentile for pleasant weather — compared to tourist destinations worldwide. Weeks with ideal weather are listed above. If you’re looking for the very warmest time to visit Portsmouth, the hottest months are July, August, and then June. See average monthly temperatures below. The warmest time of year is generally late July where highs are regularly around 72.5°F (22.5°C) with temperatures rarely dropping below 55.6°F (13.1°C) at night.
Portsmouth Temperatures (Fahrenheit)
Portsmouth Temperatures (Celsius)
Portsmouth Perceived Temperature (F)
Portsmouth Perceived Temperature (C)
Average Portsmouth Temperatures by Month
|Month||Avg. High (°F)||Avg. Mean (°F)||Avg. Low (°F)|
|Month||Avg. High (°C)||Avg. Mean (°C)||Avg. Low (°C)|
Precipitation (Rain or Snow)
If dry weather is what you’re after, the months with the lowest chance of significant precipitation in Portsmouth are March, September, and then May. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around mid March. For example, on the week of March 19th there is 1 day of precipitation on average. By contrast, it’s most likely to rain or snow in early to mid January with an average of 3 days of significant precipitation the week of January 8th.
When can you find snow in Portsmouth? Weather stations report no annual snow. Please note that a value of 0 for snow in the graph below may either mean there was no snow, or that snow is unreported.
Chance of Precipitation
The graph below shows the % chance of rainy and snowy days in Portsmouth.
Snow on the Ground
The graph below shows the average snow on the ground in Portsmouth (in).
Average Rain and Snow by Month
|Month||Daily Chance of Rain||Average Snow Depth (in)||Total Precipitation (in)|
|Month||Daily Chance of Rain||Average Snow Depth (cm)||Total Precipitation (cm)|
Humidity and Wind
Portsmouth has some extremely humid months, and high humidity throughout the year. The least humid month is June (72.5% relative humidity), and the most humid month is January (83.9%).
Wind in Portsmouth is usually moderate. The windiest month is December, followed by November and May. December’s average wind speed of around 10.7 knots (12.4 MPH or 19.9 KPH) is considered “a gentle breeze.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in mid January where average top sustained speeds reach 19.3 knots, which is considered a fresh breeze.
Relative Humidity (%)
The graph below shows the average % humidity by month in Portsmouth.
The graph below shows wind speed (max and average) in knots.
Average Wind Speeds
Show Wind Speeds
All wind speeds are in knots. 1 knot = 1.15 MPH or 1.85 KPH.
|Month||Avg. Wind||Avg. Wind Feel||Sustained High Wind||High Wind Feel|
|Jan||9.8||Gentle breeze||17.7||Strong breeze|
|Feb||8.2||Gentle breeze||15.1||Significant breeze|
|Mar||9.1||Gentle breeze||15.7||Strong breeze|
|Apr||8.9||Gentle breeze||14.8||Significant breeze|
|May||9.9||Gentle breeze||15.7||Strong breeze|
|Jun||9.4||Gentle breeze||15.1||Significant breeze|
|Jul||9.7||Gentle breeze||15.6||Strong breeze|
|Aug||9.4||Gentle breeze||15.2||Significant breeze|
|Sep||8.6||Gentle breeze||14||Strong breeze|
|Oct||9.4||Gentle breeze||15.3||Significant breeze|
|Nov||10.6||Gentle breeze||17.4||Strong breeze|
|Dec||10.7||Gentle breeze||17.9||Strong breeze|
Show Relative Humidity by Month
|Month||Avg. Relative Humidity|
Is it Safe to Travel to Portsmouth?
Our best data indicates this area is somewhat safe. As of Oct 07, 2019 there are travel warnings for the United Kingdom; exercise a high degree of caution. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Sep 06, 2019.
The Busiest and Least Crowded Months
The busiest month for tourism in Portsmouth, the United Kingdom is July, followed by September and August. Prices for hotels and flights will be most expensive during these months, though you can save if you purchase well in advance. Tourists are unlikely to visit Portsmouth in November. Those willing to visit at these times will likely find it the least expensive month.
Estimated Tourism by Month
Most Popular Months to Visit
Overall Portsmouth Travel Experience by Season
Spring (March through May)
Humidity and temperatures combine to make this season feel moderately cold. Highs range from 65°F (18.3°C) and 49.4°F (9.7°C) with warmer temperatures in the later months. Rain is somewhat common with roughly 5 days of significant precipitation per month. Spring is the second busiest for tourism, which makes it a good time for those looking for things to do.
Summer (June through August)
The middle-year months have comfortably cool weather with high temperatures that are comfortable. These months see moderate precipitation with 6 to 7 days of precipitation per month. June – August is the busiest season for tourism in Portsmouth, so lodging and other accommodations may cost more than usual.
Fall (September through November)
Fall daily highs range from 68.3°F (20.2°C) and 48.7°F (9.3°C), which will feel chilly given the humidity and wind. It rains or snows a significant amount: 5 to 9 days per month. Tourism is fairly slow during these months due to the weather, so hotels may be lower priced.
Winter (December through February)
Weather is too cold this time of year in Portsmouth to be enjoyable for warm weather travelers. The average high during this season is between 49.4°F (9.7°C) and 44.8°F (7.1°C). On average, it rains or snows a fair amount: 7 to 10 times per month. These times of year are the slowest with tourists.