Orillia, Ont. — A band of showers with a risk of thunder is expected overnight, bringing a low near 17 °C, followed by another warm day Monday with a high around 26 °C and a humidex value that could reach about 31, according to Environment Canada data.
What to expect through Monday
As of the early evening observation, the thermometer read about 23.5 °C with a dewpoint close to 16.1 °C and relative humidity near 63%. Barometric pressure was recorded at 101.7 kPa and trending lower, signalling an approaching disturbance that will increase the chance of showers and an isolated thunderstorm tonight.
Forecasters note a 40 per cent probability of precipitation for tonight and again for Monday, with an elevated risk of thunder during periods of heavier rain. Winds are light from the southeast, roughly 10 km/h, helping to keep overnight lows mild.
Seven-day outlook
The short-term outlook through the rest of the week shows a mix of sun and cloud with intermittent chances of showers. Temperatures trend slightly downward overnight, yielding cooler mornings later in the week.
| Date | Day | High | Low | Precipitation chance / notes |
|---|---|---|---|---|
| Tonight | — | — | 17 °C | 40% chance of showers; risk of a thunderstorm |
| Monday | High | 26 °C | — | 40% chance of showers; risk of thunder; humidex ~31 |
| Tuesday | High | 26 °C | 13 °C | Mostly sunny; periods of cloud at night with 40% chance of showers |
| Wednesday | High | 23 °C | 14 °C | 40% chance of showers; cloudier |
| Thursday | High | 24 °C | 11 °C | Mix of sun and cloud; 40% chance of showers |
Practical implications and planning tips
Humid conditions combined with daytime temperatures in the mid-20s mean outdoor activities may feel warmer than the thermometer indicates. The combination of a humidex near 31 and a UV index rated at 7 (high) on Monday suggests taking these precautions:
- Stay hydrated and plan strenuous activity for cooler parts of the day (early morning or evening).
- Use sunscreen with appropriate protection and seek shade during midday when UV exposure peaks.
- Have a plan for heavy downpours or lightning if you are outdoors — move indoors or to a sturdy shelter if thunder is heard.
Overnight lows will become noticeably cooler later in the week, with nighttime readings dropping to around 10–14 °C by Friday and the following nights, reflecting a shift toward drier air and clearer skies.
Sunrise, sunset and climatology
Sunrise is at 6:13 a.m. and sunset at 8:33 p.m. for the region. Normal climatological values for the period put lows near 13 °C and highs around 25 °C, so daytime temperatures for the next couple of days will be close to or slightly above seasonal averages.
Environment Canada remains the primary source for these observations and forecasts. Watch for updated forecasts if the approaching system strengthens or if thunderstorm risk changes; conditions can evolve rapidly in humid, summer air masses.
Key takeaways: expect a warm, humid night with a chance of showers and isolated thunderstorms, another warm day Monday with periods of sun and a continued risk of scattered showers, then cooler nights and more settled conditions toward the end of the week.
