It might officially be the first day of fall, but Hamilton is still firmly in the grip of summer heat.

The city issued a heat warning for this weekend, as temperatures are scheduled to soar into the 30s.

The city says humidex values are forecast to approach 40 on Saturday and Sunday.

"The unseasonably warm temperatures and humidity are likely to persist into early next week."

Environment Canada has also issued a heat warning.

The city says that as part of its heat response plan, all public, family, adult and seniors swims at all city indoor pools will be free of charge.

For more information on where you can cool down this weekend, visit