It is the hottest June 23 in Ottawa’s history, as a heat dome brings “dangerous heat and humidity” to the national capital region. The temperature peaked at 35 C at 4 p.m., setting the record for warmest June 23 in Ottawa history. With the humidex, it feels like 46. Environment Canada has issued a heat warning for Ottawa, calling for the temperature to hit 36 C today and 34 C on Tuesday. “This is the warmest moment in the last five years in Ottawa,” David Phillips, Environment Canada senior climatologist, told Newstalk 580 CFRA’s the Morning Rush with Bill Carroll. “Doesn’t matter whether it was June, July, August – the dog days of summer – it’s never been 36 degrees in the last five years.” Environment Canada says the hot and humid weather will continue until Tuesday night. “The first significant heat event of the season with dangerously hot and humid conditions is expected to continue into the week,” Environment Canada said in a statement. “Take action to protect yourself and others – extreme heat can affect everyone’s health.” The high of 35 C sets the record for warmest June 23 in Ottawa, breaking the previous record of 34.4 set in 1921. The hottest temperature recorded at the Ottawa International Airport on June 23 was 33.3 C set in 1983. “To smash a previous record of this day is quite something,” Phillips said. “And that’s in the shade.” Tuesday’s forecast high of 34 C could tie the record for the warmest June 24 in Ottawa history. It was 34.4 C on June 24, 2019. “We’re calling this heat wave dangerous. This is air from the United States but it’s under a dome, it’s like putting a lid on top of Ottawa and the air just can’t circulate,” Phillips told CTV News Ottawa on Sunday. “It sinks down the molecules vibrate and creates more heat.” The hot weather has forced some businesses to change their plans. Gia Cantina on Bank Street is closed today, saying “it’s too hot in the kitchen. Giving our team in the kitchen a break.” OC Transpo says O-Train Line 1, Line 2 and Line 4 are running at reduced speeds due to the hot temperatures. The Ottawa Fire Services has issued an open air fire ban due to the heat. Firefighters to visit apartment buildings Firefighters will be visiting Ottawa apartment buildings starting today to assess access to air conditioning. The City of Ottawa says Ottawa Fire Services staff will speak with property managers and residents to ensure that “necessary information and supports are in place. As of Sunday evening, no heat-related called had been reported to 3-1-1. Ottawa’s general manager of emergency and protective services Ryan Perrault said the Ottawa Paramedic Service has not experienced an increase in heat-related calls. The Salvation Army Outreach Van and the city’s “Community Engagement Team” are distributing water and providing information on where residents can access air-conditioned spaces. VIA Rail VIA Rail is warning travellers may experience delays on trains operating from Ottawa to Montreal and Toronto due to the heat. The Crown corporation says delays are possible on all trains operating on the Windsor-Quebec City corridor. “For safety purposes, the railway infrastructure owner could be forced to impose speed restrictions, which could result in delays at departure or on route,” VIA Rail said on X. Hottest Ottawa days Here is a look at the hottest Ottawa says since 2018. Ottawa forecast The forecast calls for mainly sunny today. High 36 C. Clear tonight. Low 25 C. Tuesday will begin with a mix of sun and cloud before becoming mainly sunny near noon. High 34 C with the humidex making it feel like 43. Wednesday will be sunny. High 28 C. It will be mainly cloudy on Thursday with a 30 per cent chance of showers. High 22 C. The outlook for Friday calls for mainly cloudy with a 60 per cent chance of showers. High 23 C. The normal temperatures for this time of year are a high of 25 C and a low of 15 C.