Ottawa will continue to experience below seasonal temperatures heading into the Mother’s Day long weekend, with overnight lows near the freezing mark. A yellow advisory - frost was issued Thursday afternoon, saying patchy frost is possible, which could damage plants, trees, and crops. “Patchy frost is expected overnight and Friday morning as temperatures drop to near or below the freezing mark,” the advisory says. “Cover up plants, especially those in frost-prone areas.” Environment Canada’s forecast calls for a high of 14 C today, 16 C on Friday and Saturday and 14 C on Sunday, with overnight lows of 1 C tonight and 2 C on Friday night. The normal temperatures for this time of year are a high of 18 C and a low of 7 C. There will be a mix of sun and cloud today with a 30 per cent chance of afternoon showers. High 14 C. Cloudy tonight. Low 1 C with the risk of patchy frost. Friday will see a mix of sun and cloud with a 30 per cent chance of showers. High 16 C. Saturday will be mainly sunny. High 16 C. The outlook for Sunday calls for mainly cloudy with a 40 per cent chance of showers. High 14 C. A mix of sun and cloud is expected on Monday with a 30 per cent chance of showers. High 15 C.