April in Aylmer averages a daily high of 11.5°C with nights around 1.4°C. Expect roughly 11.6 wet days totalling 79.5mm. Demanding conditions — pack for it and plan indoor options.
Across the year, the best time to visit Aylmer is May–September.
Based on OTTAWA CDA, ON CA (7.3km), 1995–2024. 28 years of April data.