Montréal and Ottawa have similar daytime temperatures, and both get similar annual rainfall.
Montréal is at its warmest in August and coolest in January, while Ottawa peaks in July and bottoms out in January. Month for month, Montréal is the warmer of the two in 10 of 10 months.
Both collect a similar amount of rain over the year — 1,004 mm (39.5 in) in Montréal and 966 mm (38 in) in Ottawa. The most comfortable time to visit is June, July and August in Montréal and June, July and August in Ottawa.
| Montréal | Metric | Ottawa |
|---|---|---|
| 🌡️ Temperature | ||
| 19.4°C | 🌡️Average daytime high | 19.1°C |
| -8.4°C | 🌙Average nighttime low | -9.1°C |
| August | 🔥Hottest month | July |
| January | ❄️Coldest month | January |
| 🌧️ Rain | ||
| 1,004 mm | 🌧️Annual rainfall | 966 mm |
| June | ☔Wettest month | June |
| February | 🏜️Driest month | February |
| 💨 Climate | ||
| 82% | 💧Average humidity | 84% |
| 3 m/s | 💨Average wind speed | 0.6 m/s |
Overnight, Montréal typically falls to around -8.4°C (16.9°F) while Ottawa settles near -9.1°C (15.6°F).
Montréal is hottest in August and coldest in January, whereas Ottawa peaks in July and is coolest in January.
Montréal sees the most rain in June and the least in February; Ottawa is wettest in June and driest in February.
Ottawa feels the more humid of the two, averaging 84% relative humidity against 82%.
For Ottawa, the pick of the year is June, July and August.
Month by month, here is the coldest night, the average day and the hottest afternoon each city can expect. Switch Compare to read rainfall, humidity, wind or solar instead, and Period to move between the long-term 45-year average and any single year — the shading is a quick warm-to-cool guide.
| Month | Montréal | Ottawa | ||||
|---|---|---|---|---|---|---|
| Min | Avg | Max | Min | Avg | Max | |
| January | -32.3 | -14.7❄️ | 3 | -32.5 | -15❄️ | 2.6 |
| February | -29.4 | -12.9 | 3.6 | -29.8 | -13.5 | 2.9 |
| March | -23.3 | -5.1 | 13 | -23.2 | -5.1 | 12.9 |
| April | -6.4 | 7.3 | 21 | -7.6 | 7 | 21.6 |
| May | 0.2 | 13.4 | 26.5 | -1.2 | 12.9 | 26.9 |
| June | 6.6 | 18 | 29.5 | 5.5 | 17.6 | 29.7 |
| July | 10.8 | 21🔥 | 31.2 | 9.6 | 20.2🔥 | 30.9 |
| August | 9.4 | 20.4 | 31.5 | 8.2 | 19.4 | 30.6 |
| September | 3.7 | 16.5 | 29.3 | 2.5 | 15.3 | 28 |
| October | -2.9 | 10 | 22.9 | -3.9 | 9.4 | 22.6 |
| November | -11.5 | 1.9 | 15.2 | -11.2 | 1.9 | 14.9 |
| December | -25.8 | -9.8 | 6.3 | -25.8 | -9.9 | 6 |
| Annual Avg | -8.4 | 5.5 | 19.4 | -9.1 | 5 | 19.1 |
Min / mean / max temperature (°C). 🔥 marks each city's hottest month, ❄️ its coldest; shading runs cool blue to warm red.
The same figures plotted out, so the shape of a typical year is easier to see than in a grid. Where the two lines run close together Montréal and Ottawa feel alike; where they separate, they are genuinely different places to be.
Hover or tap any point to read the exact figures. Montréal Ottawa
See how Montréal and Ottawa stack up against other cities. Swipe for more.
Choose which city to keep, then search for any other city in our database — we'll build the comparison for you.
Quick answers to the questions people ask most when comparing Montréal and Ottawa — each drawn straight from the climate figures above.
Montréal and Ottawa are about equally warm. Daytime highs average 19.4°C (66.9°F) in Montréal and 19.1°C (66.4°F) in Ottawa, so neither is clearly the warmer choice over the year. Nights are milder in Montréal, with average lows of -8.4°C (16.9°F) versus -9.1°C (15.6°F).
Montréal is hottest in August, averaging highs of about 31.5°C (88.6°F), while Ottawa peaks in July at around 30.9°C (87.6°F). That makes Montréal the hotter of the two at the height of summer.
Ottawa gets colder. In its coldest month (January) overnight lows average about -32.5°C (-26.5°F), compared with -32.3°C (-26.2°F) at the low point of the year in Montréal.
They get a similar amount of rain over a year — about 1,004 mm (39.5 in) in Montréal and 966 mm (38 in) in Ottawa. Montréal is wettest in June and driest in February; Ottawa is wettest in June and driest in February.
Humidity is similar in both, averaging around 82% in Montréal and 84% in Ottawa across the year.
The most comfortable months in Montréal are June, July and August, when average temperatures are at their mildest.
Ottawa is at its most pleasant around June, July and August, based on the mildest average temperatures of the year.
Montréal is the warmer city in all 10 months of the year. The gap is widest in September, about 1.2°C (2.2°F), and narrowest in March, about 0°C (0°F).
Both have a similar seasonal range — around 35.7°C (64.3°F) between the coldest and hottest months — so neither climate is noticeably more extreme than the other.
Every figure on this page is calculated from NASA POWER satellite climate data spanning 1981–2025 (45 years). The averages describe the long-term climate of Montréal and Ottawa, not a single year's weather or a short-range forecast.
