You’ve seen the headlines. Probably saw some "snow bomb" warning on social media or a "purple alert" map that made it look like the Arctic was moving into Zone 1. Honestly, though? London weather is rarely that dramatic, even when the wind is whipping off the Thames.
If you’re planning your week, forget the hyperbole. We’re looking at a week that starts surprisingly mild for mid-January before things get properly "winter" again.
The Immediate Outlook: Clouds and Comfort
Today, Sunday, January 18, 2026, is basically the definition of a standard London winter day. It’s 50°F (about 10°C) right now—which, let’s be real, is pretty decent for this time of year. It’s partly sunny, the wind is a tiny 1 mph coming from the northeast, and humidity is sitting high at 90%.
You might see a few sprinkles if you’re out and about, but the chance of rain is only 7%. Tonight, the temperature drops slightly to 42°F, so if you're heading out for a Sunday roast or a pint, you'll need the big coat, but you won't be freezing your ears off.
London Weather This Week: The Day-by-Day Reality
Monday and Tuesday are sticking to that mild-ish script. We’re talking highs of 49°F to 52°F. It’s overcast, it’s grey, it’s very "London."
But don't get too comfortable in that light jacket.
By Wednesday, January 21, the mercury starts to slip. We’ll see highs of 48°F, and by Thursday, it’s down to 46°F. It doesn't sound like a huge jump, but with the humidity and the wind picking up to 10 mph, it’s going to feel significantly colder.
Here is the breakdown of the shift we’re expecting:
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- Monday (Jan 19): High of 49°F, low of 41°F. Mostly overcast but staying dry.
- Tuesday (Jan 20): A peak of 52°F. This is likely the warmest part of your week.
- Wednesday (Jan 21): The "Silver Lining" day. BBC Weather and others suggest this might be the only day without constant drizzle, though it'll be a cooler 48°F.
- Thursday (Jan 22): 46°F and breezy. The dampness starts to feel a bit more biting.
- Friday (Jan 23): 46°F, but the overnight low hits 35°F. This is when things get interesting.
That Sleet Warning: Is it Actually Going to Snow?
Everyone wants to know if the white stuff is coming.
According to the latest data from BBC Weather and the Met Office, the end of this week is when the "wintry hazards" start creeping in. From Sunday, January 25, through the following Monday and Tuesday, the drizzle is expected to turn into sleet.
Why sleet? Because London is a massive heat island. While the rest of the UK might be getting a proper dusting, the capital usually hovers just a degree or two too high for snow to settle. We’re looking at highs of 41°F on Saturday and 40°F on Sunday.
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It’s that "wet cold" that gets into your bones. The kind of weather where you step in a puddle and your day is basically ruined.
What You Should Actually Do
- Layer up for Tuesday: It’s the warmest day, but the humidity means you’ll sweat in a heavy parka. Go for a breathable middle layer.
- Waterproof everything by Friday: The "sprinkles" and "drizzle" forecasts for the weekend are notoriously sneaky.
- Check the Tube: Even if it’s just sleet, the combined impact of wind and icy rain often leads to signal failures on the outdoor sections of the Metropolitan and Piccadilly lines.
Basically, the weather for london this week is a tale of two halves. Enjoy the 50°F highs while they last, because by next Sunday, you'll be dealing with 40°F and a very messy mix of rain and ice.
Keep an eye on the Met Office "Yellow" warnings toward the weekend. They haven't issued one for London yet, but as the Atlantic systems battle it out over the UK, that could change by Wednesday.
To stay ahead of the damp, check your local council's grit schedules if you're driving, as those overnight lows of 33°F (near 0°C) by next week will definitely create some slick spots on the side streets.