Portsmouth
United Kingdom
Long-term weather forecast
Long-term weather forecast

January weather forecast and climate
Portsmouth, United Kingdom

January, like December, is a frosty winter month in Portsmouth, United Kingdom, with average temperature ranging between min 3.4°C (38.1°F) and max 8.2°C (46.8°F).

Temperature

The coldest months are January and February, with an average high-temperature of 8.2°C (46.8°F).

Rainfall

In Portsmouth, during 11.2 rainfall days, 68.8mm (2.7") of precipitation is typically accumulated. In Portsmouth, during the entire year, the rain falls for 103.4 days and collects up to 699mm (27.5") of precipitation.

Sea temperature

In Portsmouth, in January, the average water temperature is 9.6°C (49.3°F).
Note: Swimming in 9.6°C (49.3°F) is considered life-threatening. Even a few minutes in 13°C (55.4°F) water is uncomfortable, and swimming below 10°C (50°F) may cause total loss of breathing control and cold shock, depending on a person's physique.

Daylight

The average length of the day in January is 8.6h.

Sunshine

In Portsmouth, the average sunshine is 2.2h.

UV index

Months with the lowest UV index are January, February, November and December, with an average maximum UV index of 1. A UV Index estimate of 2, and below, represents a low threat to health from unprotected exposure to the Sun's UV rays for average individuals.
Note: The daily maximum UV index of 1 interpret into the following advice:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.

What are the coldest months in Portsmouth?

January and February, with an average high-temperature of 8.2°C (46.8°F), are the coldest months.

What is the temperature in January in Portsmouth?

The average high-temperature, in January, is 8.2°C (46.8°F), while the average low-temperature is 3.4°C (38.1°F).

How much does it rain in Portsmouth in January?

In January, in Portsmouth, United Kingdom, the rain falls for 11.2 days. Throughout January, 68.8mm (2.7") of precipitation is accumulated.

How cold is the water in January in Portsmouth?

In Portsmouth, in January, the average water temperature is 9.6°C (49.3°F). Swimming in 9.6°C (49.3°F) is considered dangerous. Unprotected immersion in temperatures below 10°C (50°F) causes quickly maximum intensity cold shock with hyperventilation.

What is the average length of the day in January in Portsmouth?

The average length of the day in January is 8.6h.

How many hours of sunshine does Portsmouth have in January?

In January, the average sunshine in Portsmouth is 2.2h.

What are the months with the lowest UV index in Portsmouth?

January, February, November and December, with an average maximum UV index of 1, are months with the lowest UV index in Portsmouth.

What is the UV index intensity in January in Portsmouth?

In January, the average daily maximum UV index is 1. A UV Index reading of 2, and below, represents a low health risk from the exposure to the Sun's UV radiation.
Average temperature in January - Portsmouth, United Kingdom
  • Average high temperature in January: 8.2°C

Warmest months (with the highest average high temperature) are July and August (21.4°C).
Months with the lowest average high temperature are January and February (8.2°C).

  • Average low temperature in January: 3.4°C

The month with the highest average low temperature is August (14.3°C).
The coldest month (with the lowest average low temperature) is February (2.8°C).

Average rainfall in January - Portsmouth, United Kingdom
  • Average rainfall in January: 68.8mm

The wettest month (with the highest rainfall) is October (86.2mm).
The driest month (with the lowest rainfall) is June (42mm).

Average rainfall days in January - Portsmouth, United Kingdom
  • Average rainfall days in January: 11.2 days

Months with the highest number of rainy days are January and December (11.2 days).
The month with the lowest number of rainy days is July (5.4 days).

Average sea temperature in January - Portsmouth, United Kingdom
  • Average sea temperature in January: 9.6°C

The best month for swimming (with the highest average sea temperature) is September (17.3°C).
The coldest month (with the lowest average sea temperature) is March (8.6°C).

Average daylight in January / Average sunshine in January - Portsmouth, United Kingdom
  • Average daylight in January: 8.6h

The month with the longest days is June (Average daylight: 16.4h).
The month with shortest days is December (Average daylight: 8h).

  • Average sunshine in January: 2.2h

The month with most sunshine is July (Average sunshine: 8.4h).
The month with least sunshine is December (Average sunshine: 2h).

Average UV index in January - Portsmouth, United Kingdom
  • Average UV index in January: 1

Months with the highest UV index are May, June, July and August (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 1).