A cool Sunday in Ottawa with a chance of rain; frost advisory for the Valley


The weather rollercoaster known as May 2020 is nearly at an end.

After record cold and record heat and a dip back to below-seasonal temperatures, Ottawa has just one or two more days of cooler conditions before returning to a trend of seasonal and above-average temperatures.

Environment Canada's 3:30 p.m. forecast for Ottawa calls for clouds and a 60 per cent chance of showers Sunday evening. The high for the day is 15°C and the UV index is 5, or moderate.

The sky should clear overnight and drop to a low of 4°C.

June begins sunny, with a few clouds moving in by the afternoon, bringing a 40 per cent chance of showers. Monday's high is 22°C, which is right in line with seasonal norms.

A brief dip below-average Tuesday: cloudy, with showers and a high of 17°C.

Then, things start to warm up again.

Wednesday's outlook calls for a 40 per cent chance of showers and a high of 20°C.

Long-term, Thursday, Friday, and Saturday each have forecasts of a sun/cloud mix with highs of 25°C to 27°C. 

Frost in the Ottawa Valley

Environment Canada has issued a frost advisory for parts of the Ottawa valley.

The advisory says temperatures are again expected to fall to near freezing early Monday morning, resulting in patchy frost. Frost may damage frost-sensitive fruit trees and vegetable plants.

Areas under the advisory include:

  • Barry's Bay - Killaloe
  • Petawawa - Pembroke - Cobden
  • Renfrew - Arnprior - Calabogie

The forecast for these areas includes a low of 2°C.

Wild weather ride

May in Ottawa has seen record cold one week, and record heat another. 

Environment Canada's weather data for the month shows peaks and valleys. The month started off relatively warm, quickly cooled down, and then spiked up near the end before dropping back below seasonal averages. (NOTE: data for May 15 is missing)

Source: Environment Canada