Residents across Durham Region can expect a mix of warm summer temperatures, sunshine, and several rounds of thunderstorms throughout August 2026, according to the latest long-range forecast from the Old Farmer’s Almanac.
While long-range forecasts are subject to change, the outlook provides an early indication of what weather conditions may look like across Oshawa, Whitby, Ajax, Pickering, Clarington, Brock, Scugog, and Uxbridge as summer continues.
The forecast suggests August will feature alternating periods of sunshine and stormy weather, with temperatures remaining near or slightly above seasonal averages in much of southern Ontario.
Stormy Start to August
The first week of the month, August 1 to 9, is expected to begin with warm temperatures accompanied by periods of showers and thunderstorms. Residents planning long weekend activities or vacations should be prepared for changing weather conditions and monitor local forecasts for updates.
Thunderstorms during this period could bring brief heavy rainfall, lightning, and gusty winds typical of Ontario’s summer weather pattern.
Sunny Skies Return Mid-Month
Conditions are expected to improve between August 10 and 16, when sunshine becomes more dominant across much of southern Ontario.
The Old Farmer’s Almanac forecasts cooler temperatures across eastern Ontario during this period, while western parts of the province are expected to experience warmer weather. Durham Region is likely to see pleasant summer conditions with comfortable daytime temperatures and lower humidity than earlier in the season.
These conditions could provide ideal weather for outdoor festivals, sporting events, beach visits, hiking, and family activities throughout the region.
More Thunderstorms Later in August
The weather pattern is expected to shift once again between August 17 and 21, when isolated thunderstorms are forecast while warm temperatures continue across southern Ontario.
Although storms may be scattered, residents should remain alert for changing weather conditions, particularly if spending time outdoors.
Mixed Finish to the Month
The final week of August, August 22 through 31, is expected to bring another round of unsettled weather with additional thunderstorms possible.
According to the long-range outlook, eastern Ontario could finish the month with stormier conditions, while western Ontario may experience more sunshine and slightly cooler temperatures.
Temperature and Rainfall Outlook
The Old Farmer’s Almanac predicts an average August temperature of approximately 20°C across Ontario.
Eastern Ontario is forecast to experience temperatures about 1°C below seasonal averages, while western Ontario may average about 1°C warmer than normal.
Rainfall is also expected to be higher than average. Total monthly precipitation is forecast to reach approximately 125 millimetres, with eastern Ontario expected to receive around 70 millimetres above normal and western Ontario approximately 20 millimetres above average.
The forecast aligns with broader seasonal expectations that eastern Canada will experience a somewhat cooler and wetter summer than normal, while western Canada remains warmer.
Although long-range forecasts provide a useful overview of expected seasonal trends, weather conditions can change significantly as individual weather systems develop. Residents are encouraged to monitor Environment Canada forecasts for the most accurate short-term weather updates throughout August.
For now, Durham Region residents can look forward to another month of classic Ontario summer weather, featuring warm afternoons, sunny stretches, and occasional thunderstorms.
