About 275 Horizon Utilities customers are without power in the area between Barton Street to Roxborough Avenue and Gray Road to Green Road.
Horizon says the outage is weather-related.
Horizon Utilities crews have been dispatched to make repairs. The power is expected to be restored by 2 p.m. today.
At 12:40 p.m., the utility reported a second outage in east Hamilton, from the QEW to Queenston Road between Lake Avenue to Kenora Avenue, affecting 1071 customers. Restoration is estimated for 3 p.m. this afternoon.
For updates, see the company's website.