Last updated: April 22, 2025
August in Ottawa, Canada offers a delightful blend of summer warmth and refreshing evenings. Average temperatures hover around 20°C (68°F), with peaks soaring to a maximum of 32°C (89°F), making it an ideal time for outdoor activities. However, the month also brings its share of rain, with 94 mm (3.7 in) of precipitation across 13 days, highlighting the city's vibrant greenery. Expect a 67% humidity level, which can add a touch of stickiness to the warm days, but ultimately contributes to the lush and lively atmosphere of Ottawa's summer. Whether soaking in the sun or enjoying the cooler nights, August in Ottawa is a season of contrasts and beauty.
In August, Ottawa basks in warm summer days as temperatures transition into the final stretch of summer. The month typically sees minimums around 7°C (45°F) and averages about 20°C (68°F), providing a comfortable climate for both residents and visitors alike. With maximum temperatures reaching 32°C (89°F), locals enjoy plenty of sunny days perfect for outdoor activities and festivals. As the month progresses, August marks a gradual shift toward cooler temperatures, a trend that foreshadows the approaching autumn. This blend of warmth and growing crispness makes August a delightful time to experience Ottawa's vibrant culture and stunning landscapes before the chill of fall sets in.
In August, Ottawa experiences a moderate precipitation level of 94 mm (3.7 in), falling slightly below the previous month's average. With about 13 days of rain, the humidity lingers in the air, creating a muggy atmosphere typical of late summer. This pattern of precipitation reflects a trend where rainfall peaks in the mid-summer months before tapering off into autumn, as seen with July's higher total of 114 mm (4.5 in). The transition from summer to fall is marked by a gradual decrease in both total precipitation and rainy days, setting the stage for September's cooler and drier weather ahead.
In August, Ottawa experiences a notable dip in humidity, averaging around 67%, which marks the lowest level of the year. This decrease from the summer months indicates a transition towards the more comfortable fall season. Prior to August, July recorded a humidity of 69%, showing a gradual decline as the summer progresses. The trend is significant when compared to the winter months, where humidity levels soar to a humid 93% in January and February. As Ottawa moves from the sticky heat of summer into the crisp air of autumn, residents can enjoy a refreshing relief, but should also prepare for the return of increased humidity in the cooler months ahead.
In August, Ottawa continues to experience a very high UV Index of 8, consistent with the peak summer months. This level of exposure means the recommended burn time is a swift 15 minutes, urging residents and visitors alike to be vigilant about sun protection. Interestingly, August aligns closely with July, where the UV Index also reached 8, showcasing the summer's intense sunlight. As we transition into September, the UV Index begins to decline, dropping to 7, signaling a gradual shift in the sun’s intensity. With this pattern, it's essential to stay informed and shield yourself appropriately. For more insights, check out the detailed Ottawa UV Index.
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In August, Ottawa basks in a generous 315 hours of sunshine, making it the perfect time for outdoor adventures and vibrant festivals. This month, although slightly lower than July's peak of 348 hours, still maintains the summer's glorious warmth and bright skies. Following the transitions of the year, we're reminded how spring's budding warmth in May with 279 hours leads into the sun-drenched days of summer. As summer wanes, September offers 267 hours, hinting at the approaching autumn. Overall, August stands as a beautiful culmination of the summer months, shining brightly before the daylight hours gradually retreat into fall.
In August, Ottawa enjoys a 43% chance of sunny weather, positioning it as one of the more optimistic months for sunshine in the year. As summer transitions to fall, this percentage reflects a notable consistency when compared to the spring months, where sunny probabilities hover around the low to mid-40s. Interestingly, while August’s likelihood of clear skies is slightly lower than July's 35%, it signals a vibrant outdoor season worth embracing. This trend suggests that residents and visitors alike can anticipate warmer days and more sunshine, paving the way for idyllic summer activities before the cooler autumn months set in.
In August, Ottawa basks in approximately 14 hours of daylight, marking a gentle transition as summer begins to wane. The month stands as a bridge between the peak of June and July's luminous days, each offering a robust 15 hours of sunlight. As we move through August, daylight starts to taper off, leading into September's 12 hours. This gradual decrease mirrors the seasonal shift, inviting residents and visitors alike to savor the last warm evenings of summer before embracing the briskness of fall. With each passing month, Ottawa's daylight patterns vividly reflect nature's rhythm, encouraging us to cherish every golden hour.
In August, Ottawa experiences its calmest winds of the year, with an average speed of only 2.4 m/s (5 mph). This gentle breeze follows a trend of decreasing wind speeds during the summer months, peaking in March at 3.8 m/s (9 mph). From July's 2.6 m/s to August's slightly warmer 2.4 m/s, the city embraces a serene atmosphere as the height of summer settles in. As September approaches, winds pick up again to 3.0 m/s, hinting at the transitional shift towards autumn. This seasonal ebb and flow of wind not only marks the changing climate but also enhances the tranquil beauty of Ottawa's landscape during the warm August days.
The weather in Ottawa changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of August's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Ottawa and find detailed weather information for every month.
August and January present starkly contrasting weather conditions. In August, temperatures range from a minimum of 7°C (45°F) to a maximum of 32°C (89°F), with an average temperature of 20°C (68°F). This month sees approximately 94 mm (3.7 in) of precipitation over 13 days, combined with a relative humidity of 67%. In contrast, January experiences bitterly cold temperatures, with a range from -32°C (-26°F) to a maximum of 10°C (50°F) and an average of -9°C (16°F). The precipitation is slightly lower at 76 mm (3.0 in) over 9 days, but the humidity is notably higher at 93%. For more details, check out Ottawa weather in January.
August and February present strikingly different weather patterns. In August, temperatures range from a mild 7°C (45°F) to a warm 32°C (89°F), averaging around 20°C (68°F). The month is relatively humid at 67% and experiences 13 days of precipitation totaling 94 mm (3.7 in). Conversely, February plunges into frigid conditions with temperatures dropping as low as -27°C (-16°F) and averaging -8°C (18°F), peaking at just 11°C (53°F). The humidity is notably high at 93%, and precipitation occurs on 12 days, accumulating 81 mm (3.2 in). For a more detailed look at the winter weather, you can check out Ottawa weather in February.
August and March present a striking contrast in weather conditions. In August, temperatures range from a mild 7°C (45°F) to a warm 32°C (89°F), with an average of 20°C (68°F). This month experiences about 94 mm (3.7 in) of precipitation over 13 days, while the humidity averages around 67%. In contrast, March is characterized by much colder temperatures, with a minimum of -24°C (-12°F) and a maximum of 20°C (69°F), averaging -3°C (27°F). Although it sees slightly less precipitation at 87 mm (3.4 in) over 12 days, the humidity is notably higher at 86%. For a more detailed look at March weather, you can visit Ottawa weather in March.
In comparing the weather conditions of April and August, we observe significant differences in temperature and humidity. August boasts much warmer temperatures, with a minimum of 7°C and an average of 20°C, reaching highs of 32°C. In contrast, April experiences colder temperatures, ranging from a minimum of -12°C to an average of just 5°C, with a maximum of 27°C. Additionally, while August has slightly less precipitation at 94 mm over 13 days, April sees a bit more rainfall at 112 mm across 12 days and higher humidity levels at 82%. For a detailed look at April's weather, visit Ottawa weather in April.
In comparing the weather of August and May, we observe distinct differences in temperature and precipitation patterns. August typically features warmer conditions, with average temperatures reaching around 20°C (68°F), while May's average is considerably lower at 13°C (56°F). Notably, May experiences a wider range in temperatures, with a maximum of 35°C (95°F), whereas August peaks at 32°C (89°F). Regarding precipitation, May receives slightly more rainfall, totaling 117 mm (4.6 in) over 14 days, compared to August's 94 mm (3.7 in) spread over 13 days. Additionally, humidity levels are higher in May at 75%, compared to August's 67%. For more detailed insights, check out Ottawa weather in May.
When comparing the weather in August and June, we see some notable differences. August tends to be warmer overall, boasting an average temperature of 20°C (68°F), compared to June's average of 18°C (65°F). Both months experience similar maximum temperatures, reaching up to 32°C (89°F in August and 91°F in June). However, June has slightly cooler minimum temperatures, starting at 2°C (36°F), whereas August begins at 7°C (45°F). In terms of precipitation, both months are comparable, with August receiving 94 mm (3.7 in) and June slightly higher at 98 mm (3.9 in), both occurring over approximately 13 days. The humidity remains fairly constant, with August at 67% and June at 68%. For a more detailed look at the weather patterns, check out Ottawa weather in June.
In comparing the weather of July and August, July tends to be slightly warmer, with an average temperature of 21°C (70°F) compared to August's 20°C (68°F). July also experiences higher maximum temperatures, peaking at 35°C (96°F) versus August's maximum of 32°C (89°F). Precipitation is more pronounced in July, with 114 mm (4.5 in) over 12 days, whereas August sees 94 mm (3.7 in) across 13 days. Humidity levels are similar, with July at 69% and August at 67%. For more details on July's weather, check out Ottawa weather in July.
August and September showcase a notable transition in weather patterns. In August, temperatures range from a minimum of 7°C (45°F) to a maximum of 32°C (89°F), with an average temperature of 20°C (68°F). The month sees 94 mm (3.7 in) of precipitation over 13 days and a humidity level of 67%. In contrast, September experiences cooler conditions, with temperatures dipping as low as 0°C (31°F) and averaging 15°C (60°F), while still reaching a maximum of 32°C (90°F). Precipitation is slightly lower at 79 mm (3.1 in) over 11 days, accompanied by a slight increase in humidity to 72%. For more detailed information about September weather, you can visit Ottawa weather in September.
August features much warmer temperatures, with average highs reaching 32°C (89°F) and a milder minimum of 7°C (45°F). In contrast, October brings a notable drop, with average temperatures ranging from a chilly -6°C (22°F) to a milder maximum of 27°C (81°F), making it significantly cooler overall. Additionally, October experiences higher precipitation, totaling 132 mm (5.2 in) over about 12 days, compared to August's 94 mm (3.7 in) over 13 days. The increased humidity in October, at 83%, adds to the dampness associated with the season. For more details, you can check Ottawa weather in October.
August and November present notably different weather patterns. In August, temperatures can range from a mild 7°C (45°F) at night to a warm 32°C (89°F) during the day, with an average of 20°C (68°F). The month sees an average of 94 mm (3.7 in) of precipitation over 13 days, accompanied by a humidity level of 67%. Conversely, November is characterized by much colder conditions, with temperatures dropping to a minimum of -19°C (-2°F) and an average of 0°C (33°F). Though it warms to a maximum of 22°C (71°F) on occasion, the month experiences slightly more precipitation at 97 mm (3.8 in) over 14 days and a higher humidity level of 88%. For more detailed insights, you can explore Ottawa weather in November.
In August, the weather is significantly warmer, with average temperatures around 20°C (68°F) and highs reaching up to 32°C (89°F), creating a vibrant, summery atmosphere. In contrast, December brings much colder conditions, where the average temperature dips to -5°C (22°F) and can plummet to as low as -29°C (-20°F). While August experiences more precipitation over 13 days, totaling 94 mm (3.7 in), December is slightly drier with 80 mm (3.2 in) over just 12 days, despite its higher humidity level of 89%. For more details on December's weather, check out Ottawa weather in December.
As summer winds down, August in Ottawa offers a delightful mix of warm temperatures and refreshing rain, setting it apart from the rest of the year. With maximum highs that can soar up to 32°C, this month is typically one of the hottest, radiating a vibrant atmosphere that's perfect for outdoor activities. Humidity levels hover around 67%, adding a touch of mugginess that contrasts sharply with the crispness of earlier months. While rainfall is more frequent, with 13 days of precipitation, it serves to nourish the lush landscapes, creating a balance between warmth and rejuvenation. For those wanting to delve deeper into seasonal changes, visit Ottawa Climate for comprehensive insights.