Ottawa Weather Forecast
Ottawa weather: 70°F, clear. Hourly forecast, 14-day outlook, UV, air quality and the best time to visit.
Ottawa weather in September
Weather map for Ottawa
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Climate in Ottawa month by month
Average high, average low and total rainfall, based on three years of reanalysis data.
| Month | Avg high | Avg low | Rainfall | Rating |
|---|---|---|---|---|
| January | 23° | 9° | 2,4 in | ★★☆☆☆ |
| February | 27° | 9° | 1,9 in | ★★☆☆☆ |
| March | 40° | 22° | 3,1 in | ★★☆☆☆ |
| April | 52° | 34° | 5,0 in | ★★★☆☆ |
| May | 65° | 48° | 3,4 in | ★★★★☆ |
| June | 76° | 59° | 5,4 in | ★★★★☆ |
| July | 80° | 64° | 4,5 in | ★★★★☆ |
| August | 77° | 61° | 4,5 in | ★★★★☆ |
| September | 72° | 55° | 1,5 in | ★★★★☆ |
| October | 60° | 45° | 2,9 in | ★★★★☆ |
| November | 42° | 31° | 2,4 in | ★★★☆☆ |
| December | 29° | 17° | 3,5 in | ★★☆☆☆ |
Climate type: Subarctic. Source: Open-Meteo archive (ERA5).
Best time to visit Ottawa
Go in September. These months score highest on comfortable temperatures, low rainfall and useful daylight.
Hardest months: January, February and December - expect the least comfortable mix of heat, cold or rain.
What to pack, what to skip
- Sunglasses, a brimmed hat and SPF 30+
- If your dates are flexible, avoid January, February and December - historically the least comfortable months here.
How Ottawa compares with nearby places
Annual averages, and the difference against Ottawa.
| Place | Distance | Avg temp | vs here | Annual rain |
|---|---|---|---|---|
| Mont-Tremblant National Park | 90 mi | 40°F | 37°F cooler | 50 in |
| Montreal-Trudeau International Airport | 95 mi | 47°F | +33°F warmer | 43 in |
| Montreal | 103 mi | 46°F | +33°F warmer | 43 in |
| Algonquin Provincial Park | 133 mi | 42°F | 35°F cooler | 36 in |
| Burlington | 138 mi | 48°F | +35°F warmer | 45 in |
See the Ottawa forecast by time range
Ottawa weather - more answers
Explore Ottawa
Every topic we hold for this place, and the same topic for the places around it.
Weather for related places
Frequently asked questions
Where is Ottawa?
Ottawa is a city in Ontario. Its coordinates are 45.4215, -75.6972. It lies in North America.
What is the weather like in Ottawa right now?
It is currently 70°F (21°C) with clear. Humidity is 65% and wind is 5 mph.
When is the best time to visit Ottawa?
September offer the most comfortable conditions in Ottawa, which has a subarctic climate. January, February and December are usually the hardest months for outdoor plans.
What time zone is Ottawa in?
Ottawa observes America/Toronto (UTC-04:00). The local time is 8:05 PM.
How many people live in Ottawa?
Ottawa has a population of approximately 1 million.
What is the nearest airport to Ottawa?
The closest airports are Montreal-Trudeau International Airport (YUL), 95 mi away and Toronto Pearson International Airport (YYZ), 228 mi away.
What are the top things to do in Ottawa?
Popular options include Mont-Tremblant National Park, Algonquin Provincial Park, Franconia Notch State Park, Watkins Glen State Park, CN Tower and Letchworth State Park.
Related articles
Data sources and methodology
| Place data | USPOTUS Atlas dataset (cities-supported) - coordinates, hierarchy and facts. |
|---|---|
| Forecast and observations | Open-Meteo (ECMWF and national models). |
| Air quality and pollen | Copernicus CAMS via Open-Meteo. US AQI scale. |
| Climate averages | ERA5 reanalysis via the Open-Meteo archive, aggregated over 3 years. |
| Method | Scores, comparisons and advice on this page are computed from the inputs above. Distances are straight-line. Nothing is estimated where data is missing - the block is simply not shown. |
Last updated August 26, 2026 at 8:05 PM local time. Live blocks refresh every 15 minutes; climate averages monthly.
