Summer will begin at 10:42 p.m. and the first heat wave of the season will arrive soon after, with temperatures expected to top 30 C next week. Environment Canada says temperatures will warm up through the weekend, with highs of 27 C on Saturday, 31 C on Sunday, 35 C on Monday and 33 C on Tuesday. The overnight lows will stay above 20 C on Sunday, Monday and Tuesday. The normal temperatures for the first weekend of summer are a high of 25 C and a low of 14 C. The Ottawa temperature records are 36.7 C for June 21 (1921), 34.4 C on June 23 (1921) and 34.4 C on June 24 (1919). “A change of the season and a change of the weather,” David Phillips, Environment Canada senior climatologist, told CTV News Channel Friday morning. “Finally, summer looks like it’s going to arrive and not just in a teasing way. It’s going to be intensely warm and a certain duration to it. It’s going to feel like the dog days of summer.” Phillips says there will be a “certain danger” due to the heat. “It’s the first heat wave of the year; it’s always the worst. You always see more emergency room people coming in there because they’re not acclimatized to it,” Phillips said. The forecast calls for showers to end this morning then clearing. High 23 C today, with the humidex making it feel like 25. Clear tonight. Low 13 C. Saturday will start sunny with increasing cloudiness in the afternoon and a 40 per cent chance of showers. High 27 C with the humidex of 30. Sunday will see a mix of sun and cloud with a 30 per cent chance of showers. High 31 C. A mix of sun and cloud on Monday with a 30 per cent chance of showers. High 35 C. The outlook for Tuesday calls for a mix of sun and cloud with a 30 per cent chance of showers. High 33 C. Temperatures will drop to 27 C on Wednesday and 24 C on Thursday. Hot days in Ottawa The temperature has surpassed 32.5 C seven times in the past two years.