It's been been hot in Western Canada too. At my gliding club's airfield in Alberta (Black Diamond CEH2), the elevation is 3700'. Once the temperature exceeds 30° C, we implement a progressively decreasing gross weight limit for the club's two-seaters.
We've recently had density altitudes in excess of 7000'. I know that's not high by Colorado standards, but it's high enough to make our 180 HP Scout run out of steam.