London climate
London (Ontario, Canada) has a hot-summer humid continental climate (Köppen Dfa). The average temperature over the year is 9 °C48 °F, and about 660 mm26 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
London climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | −229 | −817 | −523 | 401.6 | 29 |
| Feb | −131 | −817 | −524 | 381.5 | 28 |
| Mar | 540 | −424 | 032 | 431.7 | 26 |
| Apr | 1254 | 134 | 744 | 562.2 | 13 |
| May | 1967 | 846 | 1356 | 662.6 | 1 |
| Jun | 2577 | 1356 | 1967 | 682.7 | 0 |
| Jul | 2883 | 1762 | 2373 | 702.7 | 0 |
| Aug | 2781 | 1662 | 2271 | 552.1 | 0 |
| Sep | 2474 | 1254 | 1864 | 692.7 | 0 |
| Oct | 1559 | 643 | 1151 | 622.4 | 2 |
| Nov | 846 | 033 | 440 | 502.0 | 14 |
| Dec | 135 | −424 | −129 | 441.7 | 28 |
| Year | 2883 | −817 | 948 | 66026 | 140 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 87% | 82% | 1.5 | 9:20 |
| Feb | 86% | 82% | 2.0 | 10:28 |
| Mar | 81% | 76% | 3.4 | 11:48 |
| Apr | 76% | 73% | 4.6 | 13:20 |
| May | 73% | 72% | 5.6 | 14:38 |
| Jun | 70% | 64% | 6.3 | 15:20 |
| Jul | 67% | 58% | 6.3 | 15:03 |
| Aug | 68% | 58% | 5.5 | 13:55 |
| Sep | 71% | 56% | 4.3 | 12:26 |
| Oct | 78% | 69% | 2.7 | 10:57 |
| Nov | 82% | 73% | 1.7 | 9:39 |
| Dec | 87% | 83% | 1.1 | 9:01 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of London is like
The warmest month is July, with an average high of 28 °C83 °F and a low of 17 °C62 °F. The coldest is January, when highs average −2 °C29 °F and lows −8 °C17 °F. Seasons are strongly marked: the warmest month is on average 27.5 °C49.5 °F warmer than the coldest.
Annual precipitation is moderate at about 660 mm26 in. Rain is spread fairly evenly through the year. The wettest month is July (70 mm2.7 in), the driest is February (38 mm1.5 in).
Relative humidity ranges from 67% in July to 87% in January. The clearest skies (lowest average cloud amount, 56%) are typical of September. Average wind speed near the ground ranges from 10 km/h (6 mph) in August to 17 km/h (10 mph) in January. Daylight lasts from about 9.0 hours in December to 15.3 hours in June.
A lasting snow cover is typical in December–March, when the average snow depth in the reanalysis exceeds 10 cm (deepest in January, about 18 cm).
Best time to visit London
Based on these averages, the most comfortable months for sightseeing and outdoor activities are May–September: average highs of 19 °C67 °F to 28 °C83 °F with 55 mm2.1 in to 70 mm2.7 in of precipitation per month.
The most challenging month is January, which is cold, with average highs of −2 °C29 °F.
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for London
- Winter (December–February) — highs −229 to 1 °C35 °F, lows −817 to −4 °C24 °F, about 41 mm1.6 in of precipitation a month. Pack a winter coat, hat, gloves and warm, non-slip boots and shoes with good grip, as frost is common.
- Spring (March–May) — highs 540 to 19 °C67 °F, lows −424 to 8 °C46 °F, about 55 mm2.2 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket and an extra layer for the cooler mornings and evenings.
- Summer (June–August) — highs 2577 to 28 °C83 °F, lows 1356 to 17 °C62 °F, about 64 mm2.5 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and an extra layer for the cooler mornings and evenings.
- Autumn (September–November) — highs 846 to 24 °C74 °F, lows 033 to 12 °C54 °F, about 60 mm2.4 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket.
How London compares
Compared with Brampton, about 142 km to the northeast, London is on average 0.5 °C1 °F warmer and receives 14% less precipitation (660 mm26 in vs 770 mm30 in). The difference is largest in February (1 °C1.9 °F warmer).
Of the 40 places in Canada covered by World Climates, London is the 12th warmest by annual mean temperature and the 29th wettest by annual precipitation. See all of them on the Canada climate page.
Places in other countries with the most similar temperature and rainfall pattern: Ann Arbor (United States, Dfa), Lansing (United States, Dfa) and Rochester (United States, Dfa).
Nearby places
- Kitchener 76 km · 8 °C46 °F · 762 mm30 in
- Brantford 80 km · 9 °C48 °F · 791 mm31 in
- Guelph 101 km · 8 °C46 °F · 770 mm30 in
- Brampton 142 km · 8 °C47 °F · 770 mm30 in
- St. Catharines 163 km · 10 °C50 °F · 872 mm34 in
- Windsor 164 km · 9 °C49 °F · 848 mm33 in
- Toronto 169 km · 9 °C48 °F · 774 mm30 in
- Cleveland 169 km · 11 °C51 °F · 936 mm37 in
Frequently asked questions
What is the warmest month in London?
July is the warmest month in London, with an average high of 28 °C (83 °F) and an average low of 17 °C (62 °F).
What is the coldest month in London?
January is the coldest month, with an average high of -2 °C (29 °F) and an average low of -8 °C (17 °F).
When does it rain the most in London?
July is the wettest month with about 70 mm (2.7 in) of precipitation; February is the driest with about 38 mm (1.5 in).
What is the best time to visit London?
Judging by long-term averages, the most comfortable months are May–September.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.