Weather in United Kingdom in March

March climate overview

Daytime highs across United Kingdom in March run from 10.4°C (Cornwall) to 10.5°C (London). Days over 25°C are rare anywhere in United Kingdom in March. Nights average 4.4°C; the coldest 10% of nights in Cornwall fall to 2°C or below.

Rainfall in March

Expect around 12 rainy days (1 mm or more) in March, with London the driest (10 days) and Cornwall the wettest (13 days). The wettest March at London between 1991 and 2020 was 2001 with 107 mm; the driest was 2011 with 10 mm.

Sea temperature

The sea averages 9.1°C around United Kingdom in March. That is cold for swimming without a wetsuit.

Sunshine and daylight

Around 3.5 hours of sunshine a day on average, out of 11.5 hours of daylight (sunshine estimated from cloud cover).

March against the rest of the year in United Kingdom

March is the 9th warmest month of the twelve in United Kingdom. It is 2.0°C warmer than February and 2.5°C warmer in April. The hottest month here is July (20°C) and the coolest January (8°C).

Which part of United Kingdom in March?

• Most sunshine: Cornwall, 3.5 h a day.
• Driest: London, about 10 rainy days.
• Warmest sea: Cornwall, 9°C.
• Hottest: London, 11°C by day.
• Coolest (better for walking and cities): Cornwall, 10°C.

What to pack for United Kingdom in March

Based on the averages: proper layers and a jacket - daytime highs average only 10°C; a warm layer for evenings, when it drops to around 4°C; a rain jacket - roughly 12 wet days.

Similar weather elsewhere in March

Within 1.5°C of United Kingdom's March daytime average: Paris (12°C), Thassos (12°C, sea 12°C), Istanbul (11°C, sea 8°C), Sunny Beach (11°C, sea 7°C), Budapest (11°C). See the full ranking for March.

London or Cornwall: choose by rain and evening comfort

London and Cornwall both average 10°C by day, so choosing between them will not change how warm your afternoons feel. The more useful difference is rain: London has 10 rainy days against Cornwall's 13, making it the better bet if you want to spend much of your visit outdoors. Cornwall's advantage comes after dark, with nights averaging 6°C rather than London's 3°C. That makes evenings milder, though still cool enough for a coat. Choose London if fewer interruptions from rain are your priority; choose Cornwall if milder evenings matter more and you are happy to keep plans flexible.

Expect layers, limited sunshine and cold seawater

Pack for cool days rather than assuming March will feel warm. A coat, comfortable layers and a waterproof outer layer give you room to adjust between daytime outings and colder evenings. Average sunshine is 3.5 hours a day, so do not build the whole trip around sitting in the sun. Keep outdoor plans movable and have an indoor alternative for wet spells. Cornwall's sea averages 9°C, which is cold for casual swimming; a coastal visit makes more sense for time beside the water than in it. March suits travellers comfortable with changing plans, not those relying on warmth or long sunny days.