London's weather is mild and changeable: summers are warm rather than hot, winters are cool and grey rather than freezing, and rain can fall in any month, usually as showers rather than all-day downpours. Pack layers, comfortable waterproof shoes and a light rain jacket, whatever the season.
The city's reputation for rain is a little unfair. The yearly total is modest, and it seldom rains all day. What it does have is variety. A sunny morning can turn into a cloudy, drizzly afternoon, and a cold wind by the river can make 12°C feel like 7°C.
This guide explains what the weather is really like through the year, using Met Office averages, and gives a practical packing list for each season. The figures are long-term averages (1991-2020) for the Heathrow weather station at London's western edge. Central London is usually a little warmer, especially at night.
London's climate in numbers
- Average summer high
- About 23-24°C in July and August
- Average winter low
- About 3°C in December to February
- Rain in a year
- About 615 mm, on about 112 days with 1 mm or more
- Frost
- About 27 nights a year, mostly December to February
- Sunshine
- About 1,675 hours a year; July is sunniest, December dullest
- Clocks
- BST (GMT+1) from late March to late October
The full-year picture from the Met Office
The table below gives the average daily high and low for each month, with rainfall and the number of days with at least 1 mm of rain. Remember that these are averages. A single week in May can be cooler than one in March, and a warm spell in September can feel like midsummer.
| Month | High | Low | Rain (mm) | Rainy days | Sunshine (hours) |
|---|---|---|---|---|---|
| January | 8.4°C | 2.7°C | 59 | 11.5 | 61 |
| February | 9.0°C | 2.7°C | 45 | 9.5 | 79 |
| March | 11.7°C | 4.1°C | 39 | 8.5 | 124 |
| April | 15.0°C | 6.0°C | 42 | 8.8 | 177 |
| May | 18.4°C | 9.1°C | 46 | 8.0 | 207 |
| June | 21.6°C | 12.0°C | 47 | 8.3 | 208 |
| July | 23.9°C | 14.2°C | 46 | 7.9 | 218 |
| August | 23.4°C | 14.1°C | 53 | 8.4 | 202 |
| September | 20.2°C | 11.6°C | 50 | 7.9 | 157 |
| October | 15.8°C | 8.8°C | 65 | 10.8 | 115 |
| November | 11.5°C | 5.3°C | 67 | 11.2 | 71 |
| December | 8.8°C | 3.1°C | 57 | 10.8 | 55 |
The pattern is gentle. Temperatures rise steadily from January to July and fall again through the autumn. The coldest months are rarely far below freezing, and the warmest months average in the low twenties. If you are choosing when to travel, our guide to the best time to visit London compares the seasons for crowds and prices as well as weather.
How often it really rains in London
On average, London has about 112 days a year with at least 1 mm of rain, which is less than one day in three. The totals are modest: about 615 mm a year at Heathrow. Much of that falls as light rain or passing showers, so a "rainy day" often means an hour or two of rain rather than a washed-out day.
The wettest period is autumn and early winter. October and November each average around 65 mm and 11 rainy days. The driest months by rainfall are February to April, although March and April can bring cold, heavy showers that come and go quickly. In summer, rain often comes as short, heavy showers rather than grey drizzle.
The practical lesson is to plan for showers, not to cancel plans because of them. Keep a museum, a covered market or a gallery in reserve for the wettest hour. Our list of things to do in London on a rainy day has plenty of ideas, and many of the best choices are free museums, most of which need no booking.
A hood beats an umbrella on the Thames bridges. The wind along the river and across the bridges turns umbrellas inside out surprisingly often. A light jacket with a hood copes better with showery, gusty weather, and it is easier to manage on crowded pavements and on the Tube.
Heat, sun and the occasional heatwave
London summers are usually pleasant, with average highs of about 22-24°C from June to August. Hot spells do happen, though, and they can be uncomfortable because the city is not built for heat. Many older buildings, hotel rooms and parts of the Underground have no air conditioning, and the deep Tube lines can feel much warmer than the street.
On a hot day, carry a refillable water bottle, plan outdoor sightseeing for the morning or evening, and spend the middle of the day in a museum or a shaded park. Sunshine can be strong between late spring and early autumn, so sun cream and sunglasses are worth packing even though London does not feel like a sunny destination.
If you are visiting in summer, check the forecast and any heat advice from the Met Office in the days before you travel. Our monthly guides to London in July and London in August cover the season's events.
Short days, frost and the dark months
In winter, the challenge is darkness more than cold. After the clocks go back on the last Sunday in October (25 October in 2026), afternoons get dark early, and by December daylight ends in the late afternoon. December averages only about 55 hours of sunshine in the whole month.
Frost is common but usually mild: Heathrow records around seven frosty nights a month in December and January. Snow in central London is unusual and rarely lasts, but when it does fall, even a small amount can disrupt transport, so check the status of the Tube and other lines before setting out. Damp, grey days around 5-8°C are more typical, and the damp can make them feel colder than the number suggests.
Parks, gardens and outdoor attractions shorten their hours in winter. At Kew Gardens, for example, closing time in 2026 moves to 15:15 from 12 November. Plan outdoor sights early in the day and keep museums and shops for the afternoon. For seasonal events, see our guide to London in December.
What to pack for spring (March to May)
Spring is the most changeable season. March can feel like winter; late May can feel like summer. Average highs rise from about 12°C in March to 18°C in May, but mornings and evenings stay cool.
- A warm jumper or fleece and a light, waterproof jacket.
- Long trousers or jeans, plus one lighter outfit for warm afternoons in May.
- Comfortable shoes that can cope with wet pavements.
- A scarf for March and early April, especially for evenings by the river.
- Sunglasses: spring sunshine can be bright, and May averages more than 200 hours of sun.
What to pack for summer (June to August)
Summer days are mostly warm, but London evenings can cool down quickly, and rain showers still happen. Pack as you would for a warm city, with one or two extra layers.
- Light clothes: T-shirts, shirts, dresses, shorts or light trousers.
- A light cardigan, sweatshirt or jacket for cooler evenings.
- A compact waterproof or small umbrella.
- Sun cream, sunglasses and a hat for long days outdoors.
- A refillable water bottle, useful on hot days and on the Tube.
- Swimwear if you want to try an outdoor pool such as the Serpentine Lido, which usually opens from June to mid-September.
What to pack for autumn (September to November)
September is often warm and settled, with average highs around 20°C. October and November become cooler, wetter and windier, and by late November it feels close to winter.
- Layers: T-shirts for September, plus a jumper and a medium-weight jacket.
- A properly waterproof jacket for October and November, the wettest months.
- Water-resistant shoes or boots, especially if you plan to walk in the parks.
- A scarf and light gloves for November evenings.
Autumn is a good time for long walks among the changing leaves. If you plan to explore on foot, our guide to walking in London shows which journeys are quicker on foot than by Tube.
What to pack for winter (December to February)
London winters are cold and damp rather than harsh, and January in particular tends to be grey. Average highs are about 8-9°C and lows about 3°C. You do not need heavy snow gear, but you do need warm, waterproof layers.
- A warm, waterproof coat, ideally with a hood.
- Jumpers or fleeces for layering. Indoors, museums, shops and the Tube are heated, so layers you can remove are better than one very thick coat.
- Hat, scarf and gloves.
- Warm, waterproof shoes with a good grip for wet pavements.
- Something slightly smarter for the theatre or a restaurant in the evening, if you plan to go out.
Leave the pepper spray at home. Some visitors pack self-defence spray for walking at night. Pepper spray and CS gas are banned goods at the UK border, so do not bring them. Our guide to UK customs rules lists other items you cannot bring in.
Items to pack in any season
A few things are useful whenever you travel to London:
- A plug adapter. The UK uses the three-pin BS 1363 plug, and the supply is 230 V at 50 Hz. Check that devices from North America can handle 230 V. Our guide to UK plugs and voltage explains the details.
- A contactless card or phone wallet. Buses do not accept cash, and contactless is the easiest way to pay for the Tube. Keep your phone charged: a flat battery means you cannot touch out.
- Comfortable walking shoes. Most visitors walk far more than they expect in London, even when they use the Tube.
- A small day bag that closes securely, for your phone, wallet and waterproof layer.
- Your ETA or visa details and your passport. Many visitors need a UK ETA before they travel.
Visitors from the EU should also know that meat and dairy products (including sandwiches and cheese) cannot be brought into Great Britain from EU countries for personal use.
Reading the London forecast
Because London's weather changes quickly, the forecast for the next two or three days is much more useful than a forecast made a week earlier. Check it each evening and plan the next day around it: outdoor sights in the drier half of the day, indoor ones for the rest.
A forecast of "showers" usually means rain on and off, with sunny spells between. "Rain" or "persistent rain" is more likely to last for hours. For official warnings of severe weather, such as heat, strong winds or snow, the Met Office is the authoritative source.
Frequently asked questions
Does it rain every day in London?
No. On Met Office averages, London has about 112 days a year with at least 1 mm of rain, which is fewer than one day in three. Most rain falls as showers that last an hour or two, so you can usually carry on sightseeing with a hood or a small umbrella.
What is the hottest month in London?
July is the warmest month, with an average daily high of 23.9°C at Heathrow, followed closely by August at 23.4°C. Occasional heatwaves bring much higher temperatures, which can feel uncomfortable because many buildings and parts of the Tube have no air conditioning.
Does it snow in London?
Snow does fall in some winters, but it is unusual in central London and rarely stays on the ground for long. Cold, damp days of 5-8°C with the occasional frosty night are much more typical. If snow does fall, check transport status before travelling.
Do I need an umbrella in London?
A small umbrella is useful, but a light waterproof jacket with a hood is often more practical, because wind along the river can wreck umbrellas and they are awkward on crowded pavements. Many visitors carry both in autumn and winter.
What should I wear in London in autumn?
Layers work best. In September, T-shirts and a light jacket are usually enough. By October and November, add a jumper, a waterproof jacket and water-resistant shoes, and a scarf for the evenings, as it becomes cooler, wetter and darker.
Sources
- Met Office - Heathrow climate averages 1991-2020 (checked September 2026)
- GOV.UK - When do the clocks change? (checked September 2026)
- legislation.gov.uk - Electricity Safety, Quality and Continuity Regulations 2002, regulation 27 (checked September 2026)
- GOV.UK - Bringing goods into the UK for personal use (checked September 2026)
- GOV.UK - Bringing food into Great Britain (checked September 2026)
- Royal Botanic Gardens, Kew - Opening and closing times (checked September 2026)