Monthly weather averages & travel planning

Europe › 🇬🇧 United Kingdom › London
Updated: March 2026
August is a good time to visit London (7/10). With 10 daily sunshine hours and only 10 rain days, this month delivers genuinely reliable outdoor conditions, ranking it 4th sunniest of the year in London. Culture-focused travellers and those who prefer lighter crowds will find August a practical choice, with prices running lower than peak June without sacrificing all the good weather. Notting Hill Carnival takes place this month, adding cultural value for those planning around it. The main practical note: London's popular sites are busiest between 10am and 3pm regardless of season. Arriving at opening time or after 4pm makes a significant difference to the experience. Planning tips: accommodation is generally available without long lead times, and flight prices are typically lower than peak season. Flexible travellers will find the best deals by booking 2-4 weeks ahead. Mid-week arrivals consistently unlock lower hotel rates than weekend check-ins.
Step off the plane in London in August and the air meets you at around 21°C, a temperature that feels genuinely welcoming after a long flight. By the time evening arrives and temperatures settle near 13°C, the city takes on a different character entirely. With 10 hours of daylight sun on offer, August gives you the raw material for a genuinely memorable trip.
21°C
70°F
Avg High
13°C
55°F
Avg Low
10 days
61 mm total
Rain Days
10h
per day avg
Sunshine
65%
Moderate
Humidity
The 8°C day-night temperature range is typical for continental climates: a light jacket in the morning that you shed by midday and need again after sunset. Humidity averages 65%, which is comfortable for most visitors. On warmer days, lighter fabrics help with the mild stickiness in the afternoon. UV index averages 10 this month, classed as high to very high. SPF 30+ sunscreen, a brim hat, and sunglasses are not optional between 10am and 4pm. Wind averages 18 km/h, light enough to be refreshing on warm days but noticeable in open coastal areas or elevated viewpoints. In Fahrenheit: 70°F average high, 55°F overnight low. Data sourced from Open-Meteo ERA5 climate reanalysis (1991–2020 normals).
Packing for London in August means dressing for 21°C days and 13°C evenings. A light cotton tee with a casual overshirt works well at 21°C, the overshirt doubles as a layer for air-conditioned venues. Evening temperatures settle at 13°C, a modest 8°C drop that a light cardigan or denim jacket covers. European cobblestones reward low-profile walking shoes over flip-flops or heels, with cushioned trainers or leather walking shoes being the practical choice. A compact foldable umbrella weighs almost nothing and earns its keep across 10 potential rainy days.
Local tip: Many of London's museums and galleries maintain cool interior temperatures regardless of outdoor conditions. A compact layer in your daypack lets you move between warm streets and chilled exhibition halls without discomfort.
August Bank Holiday Weekend
Europe's largest street festival, celebrating Caribbean culture. Over 1 million attendees over two days. Steel bands, sound systems, Caribbean food, and elaborate costumes along a 9-mile route.
LondonBased on 21°C average highs and 10 rainy days
August in London reflects a mid-latitude climate pattern, with temperatures averaging 21°C by day and 13°C overnight. The city sits at 52 degrees north latitude, where the balance between solar radiation and heat loss drives conditions that are neither extreme nor static. Conditions occupy the comfortable middle band of the annual temperature range, where outdoor activity is feasible without the extremes of midsummer heat or midwinter cold. Day-to-night temperature variation of 8°C is moderate and manageable with a single mid-layer. Climate data: Open-Meteo ERA5 (1991–2020).
Sunshine Hours
The average number of hours per day with direct sunlight. Calculated from satellite measurements. Days with more than 7 hours of sunshine are ideal for outdoor activities. Under 3 hours means overcast conditions dominate.
UV Index
A scale from 0-11+ measuring ultraviolet radiation intensity. UV 0-2: Minimal risk. UV 3-5: Moderate, wear sunscreen. UV 6-7: High, hat and SPF 30+ essential. UV 8-10: Very High, limit midday exposure. UV 11+: Extreme, seek shade between 10am-4pm.
Rain Days
A rain day is counted when precipitation exceeds 0.1mm. This threshold captures even light drizzle. Unlike total rainfall in mm, rain days tells you how often you might need an umbrella, which is useful for planning outdoor activities.
Humidity
Relative humidity as a percentage. Below 40%: Dry, skin and throat may feel parched. 40-60%: Comfortable, ideal for most people. 60-80%: Sticky, light breathable fabrics recommended. Above 80%: Muggy, heat feels more intense; quick-dry clothing is essential.
London in August
August ranks 4th sunniest of the year in London, with an average 10 daily sunshine hours. The driest months are September, February, and March. July is the hottest month (22°C avg high); January is the coolest (7°C). From here, temperatures fall 2°C into September. Compared to last month (July: 22°C high, 11 rain days), August is cooler and drier. August sits in the middle of the annual sunshine ranking for London, offering a reasonable balance of good weather and manageable crowds.
| Month | High | Low | Rain Days | Sun | Details |
|---|---|---|---|---|---|
| January | 7°C | 2°C | 11 | 4h | View |
| February | 8°C | 2°C | 10 | 5h | View |
| March | 10°C | 3°C | 10 | 7h | View |
| April | 14°C | 5°C | 11 | 9h | View |
| May | 17°C | 8°C | 10 | 10h | View |
| June | 20°C | 11°C | 10 | 11h | View |
| July | 22°C | 13°C | 11 | 11h | View |
| August | 21°C | 13°C | 10 | 10h | View |
| September | 19°C | 11°C | 9 | 8h | View |
| October | 15°C | 8°C | 11 | 6h | View |
| November | 10°C | 5°C | 11 | 4h | View |
| December | 8°C | 3°C | 11 | 4h | View |
January
11 rain days, 4h sun
February
10 rain days, 5h sun
March
10 rain days, 7h sun
April
11 rain days, 9h sun
May
10 rain days, 10h sun
June
10 rain days, 11h sun
July
11 rain days, 11h sun
August
10 rain days, 10h sun
September
9 rain days, 8h sun
October
11 rain days, 6h sun
November
11 rain days, 4h sun
December
11 rain days, 4h sun
Cities within 500 km with comparable weather conditions
Data Sources for London
Climate normals represent 30-year averages (1991-2020). Individual years may vary.