A sunny Saturday in Brockville. (Nate Vandermeer / CTV News Ottawa)

Sunday is looking hot and humid, with a fair amount of sunshine, but a risk showers and even possible thunderstorms are in the forecast.

A heat warning ended for Ottawa late Friday, but the warning continues for some parts of eastern Ontario along the St. Lawrence River, including Kingston and Napanee.

In Ottawa, the forecast calls for sunshine most of the day, with a high of 30°C and a humidex of 35. The UV index is 10, or very high.

By mid-afternoon, Environment Canada says there is a 40 per cent chance of showers with the risk of a thunderstorm into the early evening.

The sky is expected to clear in the evening. The overnight low is 16°C.

Monday's forecast calls for sunshine and a high of 30°C with a humidex of 33 and a UV index of 9, or very high.

A sun/cloud mix is in the outlook for Tuesday, with a high of 32°C.

High temperatures in the low 30s are expected to continue through the week, with overnight lows in the low 20s.