London, England Weather by Month, Compared With Toronto and Vancouver

For a Canadian, that means far milder winters than Toronto, cooler summers, and a little over half the yearly rain and snow of Vancouver.

London's forecast is worth checking each morning, and a HelloRoam UK travel eSIM gives you mobile data for the Met Office app, maps and Tube status from the arrivals hall onward.

London's Average Temperature, Rain and Sunshine by Month

The table below gives the Met Office averages for Heathrow for 1991 to 2020, the latest 30-year period. Temperatures are rounded to one decimal place, and rain and sunshine to whole numbers.

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November is the wettest month at Heathrow, with 67 mm of rain, and October is close behind with 65 mm. March is the driest, with 39 mm. Rain falls in every month: each one has between 7.9 and 11.5 days with at least 1 mm.

Sunshine changes far more than rain. July averages 218 hours of sunshine, while December gets 55 hours for the whole month, under 2 hours a day.

London Has Milder Winters Than Toronto and About Half of Vancouver's Rain

Environment and Climate Change Canada publishes averages for the same 1991 to 2020 period, so Heathrow can sit next to Toronto Pearson and Vancouver International. The Met Office lists London's total as rainfall; the Canadian totals count rain plus snow, measured as water.

London is far milder than Toronto in winter. Heathrow's average January low of 2.7°C is warmer than Toronto Pearson's average January high of -1.2°C. In July the order flips: Toronto's average high of 27.4°C beats London's 23.9°C.

Vancouver is the closest match in temperature. Its January high of 6.8°C sits near London's 8.4°C, and its July high of 22.4°C is close to London's 23.9°C. Vancouver is much wetter, though, with 1,159.5 mm a year against London's 615 mm.

Toronto gets more precipitation than London in a year (806.8 mm), but London has slightly more days with at least 1 mm (111.7 against 105.5).

Winter in London Is Damp and Mild, With Little Snow

From December to February, Heathrow averages highs of 8.4°C to 9.0°C and lows of 2.7°C to 3.1°C. Nights can still freeze: January averages 6.8 days of air frost and December 7.2.

The Met Office's Heathrow averages do not count snow. Across the whole UK, the Met Office records an average of 13.0 days a year with snow lying on the ground (1991 to 2020), and most of it is in mountain areas. The UK's most common wind is south-westerly, which the Met Office says usually brings mild Atlantic air and rain rather than snow. Toronto Pearson, by contrast, averages 114.5 cm of snowfall a year.

Hyde Park Winter Wonderland runs from 19 November 2026 to 3 January 2027, open every day except Christmas Day. For a winter trip, pack a warm mid-layer, a waterproof jacket and shoes that cope with wet pavements. A heavy Canadian parka is more than most London winter days need.

Spring Warms From 11.7°C in March to 18.4°C in May

March averages a high of 11.7°C and a low of 4.1°C, with 124 hours of sunshine. April's average high reaches 15.0°C. May averages a high of 18.4°C and a low of 9.1°C, with 46 mm of rain on 8.0 days and 207 hours of sunshine. May can also bring a heat spell. On 26 May 2026, Kew Gardens in London reached 35.1°C, England's highest May temperature in Met Office records.

June is about 3°C warmer than May, with an average high of 21.6°C, and it gets almost the same rain (47 mm) and sunshine (208 hours). Choosing between the two comes down to how warm you want your days.

The RHS Chelsea Flower Show runs from 18 to 22 May 2027, with public days from 20 May.

Summer Highs Peak at 23.9°C in July, but Heat Waves Have Set Records

July and August are the warmest months, with average highs of 23.9°C and 23.4°C and lows near 14°C. They are also among the sunniest, with 218 and 202 hours of sunshine.

Heat waves can push far past those averages. The Met Office has confirmed the UK's highest temperature on record, 40.3°C at Coningsby in Lincolnshire on 19 July 2022, the first time the UK passed 40°C. London's highest reading came the same day, with 40.2°C at both Heathrow and St James's Park. That is the record for south-east and central southern England in the Met Office's list of UK climate extremes. So London has never reached 45°C.

Summer 2026 was provisionally the UK's warmest on record, with a mean temperature of 16.5°C, ahead of 2025's 16.1°C, the Met Office reported in its summer 2026 statistics on 1 September 2026. The season's highest reading was 38.2°C, at Hartpury College on 13 August.

For a summer trip, pack light layers and a thin rain shell: July and August still average about 8 days each with at least 1 mm of rain.

Autumn Turns Wetter Through October and November

September still averages a 20.2°C high and 157 hours of sunshine, with 7.9 days of at least 1 mm of rain. October drops to a 15.8°C high, with 65 mm of rain on 10.8 days. November averages an 11.5°C high, with 67 mm of rain on 11.2 days and 71 hours of sunshine.

From October onward, a waterproof jacket and shoes with good grip matter more than a heavy coat.

The Met Office Forecast Covers 14 Days, in Two Levels of Detail

Just before and during your trip, use the Met Office forecast for London. It gives hourly detail for the first 7 days. For days 8 to 14, it shows a daily outlook for rain, wind and temperature, a range of possible outcomes and a certainty level, and the Met Office says that outlook may change as the date gets closer.

The Met Office also posts current UK weather warnings. Check them before a travel day, and check with your airline if a warning covers your flight.

What your insurance pays if weather disrupts a trip depends on the policy, so read our guide to travel insurance for Canadians before you buy one.

The Best Time to Visit London Depends on the Weather You Want

The Heathrow averages above point to four kinds of trip:

• Mild and bright: May, June and September, with average highs of 18.4°C to 21.6°C and 157 to 208 hours of sunshine.
• Warmest: July and August, with highs near 24°C and 202 to 218 hours of sunshine, plus the chance of a heat wave.
• Driest: March, with 39 mm of rain, though highs average only 11.7°C.
• Festive: late November and December, when Hyde Park Winter Wonderland is open, with highs of 8.8°C to 11.5°C and short, grey days.

For most Canadian travellers, May and September give the best mix: highs of 18°C to 20°C, almost no frost, and fewer rain days than winter.

Getting Online on a Canadian Phone in London

Check what your Canadian carrier charges to roam in the UK. Rogers, for example, lists a daily roaming fee and Travel Passes for trips of 3 to 30 days on its roaming page as of October 2026. For a day or two in London, that can be the simpler choice. Our guide to roaming costs for Canadians in Europe compares those options with eSIM plans.

A HelloRoam UK eSIM connects to local UK networks. Its plans use EE, with 5G, and Three, with 4G. Install it at home on Wi-Fi. After you land, turn on the eSIM line, choose it for mobile data and turn on data roaming for it.

Keep your Canadian line on for calls and texts, with its mobile data turned off; calls and texts on it follow your carrier's roaming rules. On an iPhone or a Pixel, you can also turn off data roaming for the Canadian line alone. On a phone with one data roaming switch for both lines, such as many Samsung Galaxy models, leave data roaming on.

Before you buy, check that your phone supports eSIM and is unlocked. Since 1 December 2017, the CRTC's Wireless Code has given individual wireless customers in Canada the right to have a phone unlocked free of charge on request.

If eSIMs are new to you, start with our page on what an eSIM is. Our guide to installing an eSIM before you fly covers iPhone and Android.

As of October 2026, TfL says about 70% of below-ground Tube stations have a mobile signal, and EE and Three are among the four networks in the rollout. Every Tube station also has Wi-Fi, provided through UK mobile networks' own Wi-Fi services, but there is no Wi-Fi signal in the tunnels.

If London is one stop on a longer trip, a HelloRoam Europe data plan covers the UK and other European countries on one eSIM.