Best time to visit Longueuil
The best time to visit Longueuil is September, judged on twenty years of weather records and the events worth going for.
Longueuil, Quebec, Canada
°C
mm
- Average daily high and low
- Precipitation
- Good month
- Best month
- Made good or best by an event
| Month | Average daily high | Average daily low | Precipitation | Verdict |
|---|---|---|---|---|
| January | -4.3 °C / 24 °F | -12.3 °C / 10 °F | 72 mm / 2.8 in | neither best nor good |
| February | -3 °C / 27 °F | -11.8 °C / 11 °F | 67 mm / 2.6 in | neither best nor good |
| March | 3.3 °C / 38 °F | -5.6 °C / 22 °F | 77 mm / 3 in | neither best nor good |
| April | 11.7 °C / 53 °F | 1.9 °C / 35 °F | 109 mm / 4.3 in | neither best nor good |
| May | 19.7 °C / 67 °F | 8.9 °C / 48 °F | 98 mm / 3.9 in | good month |
| June | 23.9 °C / 75 °F | 14.1 °C / 57 °F | 122 mm / 4.8 in | good month |
| July | 26.6 °C / 80 °F | 17 °C / 63 °F | 105 mm / 4.1 in | good month |
| August | 25.4 °C / 78 °F | 15.7 °C / 60 °F | 112 mm / 4.4 in | good month |
| September | 21.4 °C / 71 °F | 11.4 °C / 53 °F | 88 mm / 3.5 in | best month |
| October | 14 °C / 57 °F | 5.6 °C / 42 °F | 120 mm / 4.7 in | neither best nor good |
| November | 6 °C / 43 °F | -1.1 °C / 30 °F | 82 mm / 3.2 in | neither best nor good |
| December | -1.1 °C / 30 °F | -7.8 °C / 18 °F | 99 mm / 3.9 in | neither best nor good |
Good and best months depend on more than temperature, rain and events. How they are chosen
Each activity on this page has its own good and best months, rated on twenty years of daily weather records. Which measures count, and how much, depends on the activity: humidity for exploring outdoors, wind for the beach, hiking and skiing, snow for skiing alone. Between them, the activities are rated on:
- Daytime highs
- Night-time lows
- How warm it feels
- Humidity
- How much of the day is sunny
- Hours of daylight
- Monthly rainfall
- How many days it rains
- Days of heavy rain
- Wind
- Snowfall and days with snow
- Major events, such as festivals
The chart shows the good and best months for exploring outdoors.
The event icon marks a month that an event lifts to good or best, such as a festival or a natural spectacle. Choose “Weather only” in the toolbar to rate the months on weather alone.
Best months by activity
Exploring outdoors
Mild days and nights, mostly dry and bright. The default for 'when should I go'.
- JJanuary: neither
- FFebruary: neither
- MMarch: neither
- AApril: neither
- MMay: good
- JJune: good
- JJuly: good
- AAugust: good
- SSeptember: best
- OOctober: neither
- NNovember: neither
- DDecember: neither
- Best
- September
- Good
- May–August
Why these months
May · good
In its favour: feels like (high) 17.9 °C / 64 °F, average daily high 19.7 °C / 67 °F, share of daylight that is sunny 70%, precipitation 98 mm / 3.9 in, relative humidity 64%, days with heavy rain 3.5 days, average daily low 8.9 °C / 48 °F.
Against: wet days 12.2 days.
June · good
In its favour: feels like (high) 23.9 °C / 75 °F, average daily high 23.9 °C / 75 °F, share of daylight that is sunny 71%, precipitation 122 mm / 4.8 in, average daily low 14.1 °C / 57 °F, relative humidity 70%, days with heavy rain 4.3 days.
Against: wet days 13.8 days.
July · good
In its favour: feels like (high) 27.9 °C / 82 °F, share of daylight that is sunny 80%, average daily high 26.6 °C / 80 °F, precipitation 105 mm / 4.1 in, average daily low 17 °C / 63 °F, days with heavy rain 3.5 days, relative humidity 73%.
Against: wet days 12.6 days.
August · good
In its favour: feels like (high) 26.3 °C / 79 °F, average daily high 25.4 °C / 78 °F, share of daylight that is sunny 81%, precipitation 112 mm / 4.4 in, average daily low 15.7 °C / 60 °F, days with heavy rain 3.4 days, relative humidity 75%.
Against: wet days 12.4 days.
September · best
In its favour: feels like (high) 20.9 °C / 70 °F, average daily high 21.4 °C / 71 °F, share of daylight that is sunny 76%, precipitation 88 mm / 3.5 in, wet days 9.2 days, days with heavy rain 3 days, average daily low 11.4 °C / 53 °F.
Against: relative humidity 78%.
An activity is listed only where it applies: skiing at ski destinations, beach and swimming at beach destinations. The nearest ski area is Bromont Montagne d'Expérience, 68 km away.
Weather averages
Monthly averages over twenty years, 2006–2025. Highs, lows and precipitation are in the chart at the top.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels like (high) | -9.2 °C | -8 °C | -1.3 °C | 7.9 °C | 17.9 °C | 23.9 °C | 27.9 °C | 26.3 °C | 20.9 °C | 11.4 °C | 2.2 °C | -5.5 °C |
| Days with heavy rain | 2 days | 1.9 days | 2.5 days | 4.2 days | 3.5 days | 4.3 days | 3.5 days | 3.4 days | 3 days | 4 days | 3 days | 3.3 days |
| Time rain usually falls | 10 am | 6 pm | 4 pm | 6 pm | 9 pm | 5 pm | 3 pm | 5 pm | 5 pm | 4 pm | 12 am | 8 am |
| Sunshine per day | 5.7 h | 6.9 h | 8.3 h | 9.1 h | 10.5 h | 11.1 h | 12.1 h | 11.4 h | 9.5 h | 7.2 h | 5.9 h | 4.8 h |
| Relative humidity | 77% | 74% | 68% | 64% | 64% | 70% | 73% | 75% | 78% | 77% | 77% | 80% |
Air quality
Averaged over a shorter period (2022–2025) than the twenty-year averages above, and not counted towards good or best months.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Air pollution (PM2.5) 2022–2025 | 9.4 µg/m³ | 11.6 µg/m³ | 11.5 µg/m³ | 10.2 µg/m³ | 10.8 µg/m³ | 17.9 µg/m³ | 15.3 µg/m³ | 12.4 µg/m³ | 11.3 µg/m³ | 8.3 µg/m³ | 7.2 µg/m³ | 9.3 µg/m³ |
| Air pollution (PM2.5, daily peak) 2022–2025 | 16.8 µg/m³ | 21.5 µg/m³ | 20.8 µg/m³ | 18.2 µg/m³ | 19.6 µg/m³ | 30.1 µg/m³ | 24.9 µg/m³ | 21.1 µg/m³ | 20.1 µg/m³ | 14.5 µg/m³ | 12.9 µg/m³ | 17.4 µg/m³ |
- Good 15 µg/m³ or less
- Fair 15 to 25 µg/m³
- Moderate 25 to 37.5 µg/m³
- Poor 37.5 to 50 µg/m³
- Very poor 50 to 75 µg/m³
- Extremely poor over 75 µg/m³
Each figure is compared with the World Health Organization's guideline for a day's air, 15 µg/m³ or less, and with its interim targets above that. The words are ours: the WHO does not name its steps. The figures are modelled monthly averages, so single days can be well above them. The daily peak is the average of each day's highest hour, shaded on the same scale.