Good morning, London.
Wednesday 20 May 2026 arrives on the tail end of a squally night, with the Met Office confirming that the heavy and blustery showers that rolled across the capital through Tuesday evening are now gradually easing as we move into the early hours. The overnight temperature has settled at around 13°C — notably milder than the seasonal average — thanks to a thick blanket of cloud acting as an insulating lid over the city.
Through the morning, Londoners can expect a largely overcast sky with the cloud beginning to break and allow brighter spells to develop during the afternoon. The daytime high is forecast to reach 20°C — warm for mid-May — with a brisk but not unpleasant breeze keeping things fresh. A 20% chance of isolated light showers persists, mainly in the morning hours and particularly over higher ground in the west of Greater London. By evening, conditions should be broadly dry and reasonably comfortable.
Met Office Advisory: Heavy and blustery showers from Tuesday night are gradually easing through early Wednesday morning. Expect a largely cloudy start with brighter intervals developing into the afternoon. Remain prepared for isolated spots of light rain, particularly in western areas.
The good news for the days ahead is considerable: the Met Office signals that conditions are set to turn notably drier, brighter, and warmer from Thursday. Friday and Saturday look positively summery with temperatures potentially nudging 27°C — with only a small risk of isolated thundery showers on Friday evening to temper the enthusiasm. If you have outdoor plans for the weekend, start preparing now.
Detailed Conditions
Temperature & Feels-Like
The overnight low of 11°C means this is one of the milder mid-May nights in recent years — typical for a southwesterly airflow keeping Atlantic warmth pushed across the UK. Through the day, temperatures will climb steadily to reach 20°C in the early afternoon. However, with a brisk breeze in play, the feels-like temperature will sit a couple of degrees lower — around 17–18°C in exposed areas such as riverside paths, parks, and elevated spots like Hampstead Heath or Crystal Palace. Dress with a light layer you can remove by midday.
Wind
Winds are coming predominantly from the west-southwest at 15–20 mph, with gusts potentially reaching 28–32 mph during the morning as the last of Tuesday's showers clear. This is classed as a "fresh breeze" on the Beaufort scale — enough to make umbrellas awkward and to ruffle hair noticeably. Conditions will ease slightly through the afternoon, making outdoor lunch breaks and evening walks more agreeable. Cyclists should allow extra time heading into a westerly headwind on central London routes.
Rain & Cloud
The morning commute (roughly 06:00–09:00) carries the highest risk of residual showers, with precipitation probability hovering around 40–50% before dropping sharply to under 20% by late morning. Total accumulation, should showers occur, is expected to be light — no more than 2–5mm over the day. Cloud cover will be extensive throughout the morning (80–90%) but begins thinning meaningfully from noon onwards, with genuine sunny intervals likely between 13:00 and 17:00. Visibility is expected to be good to very good once the showers clear, with no fog concerns.
Humidity & Air Quality
Following overnight rainfall, morning humidity will be elevated at 80–90%, giving that characteristic damp-London feel to the air. This will drop considerably through the afternoon — expect 50–65% by midday, which is comfortable and well within healthy ranges. Air quality is rated Low today, meaning excellent conditions for those with respiratory conditions, allergy sufferers, and anyone exercising outdoors. Pollen levels remain moderate for mid-May, however — hay fever sufferers should take their antihistamines.
UV Index
With thick cloud dominating the morning hours, UV exposure will be minimal (index 1–2) until midday. As brighter intervals develop in the afternoon, the UV index may reach 3–4 (moderate). While this is not extreme, it is sufficient to cause sunburn with extended unprotected exposure — particularly between 12:00 and 16:00. If you plan to spend the afternoon outdoors, SPF 30 sunscreen remains a sensible precaution.
Sunrise & Sunset
With mid-May's long days well established, sunrise this morning is at 05:03 BST and sunset falls at 21:01 BST — giving Londoners just under 16 hours of daylight to enjoy. Evening light will be particularly lovely if skies clear as forecast, casting that golden late-spring glow across the Thames.
Precautions Before You Head Outside
Before you leave home today, here is what the WeatherLondon.uk team recommends:
Carry a compact umbrella
Showers are most likely during the morning commute. A folding umbrella in your bag is essential — but be aware of gusts that may turn it inside-out. A wind-resistant design is preferable.
Layer up smartly
Start with a light waterproof or windproof jacket over a t-shirt or light jumper. You will want it off by lunchtime but will be grateful for it during the breezy, damp morning.
Take your antihistamines
Pollen levels are moderate for May. Grass pollen season is beginning to peak, and damp conditions followed by afternoon sunshine can trigger a sudden release of pollen as things dry out.
Cyclists: allow extra time
Wet roads in the morning increase stopping distances significantly. Brakes and tyres take longer to respond on damp tarmac. Ride to conditions and avoid puddles near kerbs, which can hide potholes.
Wear sensible footwear
Pavements will be wet and potentially slippery, especially on tiled surfaces around Tube stations and outside cafés. Leave the smooth-soled shoes at home — trainers or light boots with grip are ideal.
Apply SPF for the afternoon
UV levels rise to moderate once the cloud breaks after noon. A quick application of SPF 30 before heading out for lunch will protect against cumulative sun exposure you might not notice until later.
Dog walkers: early is soggy
Parks and green spaces will be saturated from overnight rain. Hyde Park, Hampstead Heath, and Victoria Park paths will be muddy. An early afternoon walk, once things have brightened, will be far more pleasant.
Drivers: watch spray & glare
Wet roads produce significant spray — ensure your windscreen wipers are in good condition and dipped headlights are on during the morning showers. Allow extra stopping distance from the vehicle in front.
How Does Today Compare Historically?
The average high for London in mid-May is around 17–18°C, which means today's forecasted peak of 20°C sits comfortably above the seasonal norm. The overnight low of 11°C is also warmer than the historical average of around 9°C for this time of year, a pattern consistent with the milder-than-average spring the United Kingdom has experienced in 2026. May typically brings around 25 rainy days over the month with roughly 60mm of total rainfall — today's residual showers are very much in keeping with typical mid-May behaviour, even if the warmth is somewhat exceptional.
The improving forecast for later in the week aligns with a well-established meteorological pattern: once the Atlantic low-pressure systems that dominate the earlier part of the week clear eastward, the door opens for high-pressure ridges to advance from the Azores, bringing the kind of settled, sunny weather that Londoners will be hoping to savour through the Bank Holiday weekend.
Final Thoughts for Today
Wednesday 20 May 2026 is very much a day of two halves for London. Greet the morning with pragmatism — waterproof jacket, sturdy shoes, umbrella in hand — and reward yourself with the afternoon, when the city should brighten beautifully and temperatures climb to a very pleasant 20°C. The weekend ahead promises something genuinely spectacular, so use today to make plans, charge your outdoor speakers, and dust off those garden chairs.
Stay safe, stay dry in the morning, and enjoy the sunshine when it arrives. We will have a full updated forecast for Thursday morning published by 06:00 BST tomorrow. Follow WeatherLondon.uk for the latest.
