Since I'm bored, I looked up the hourly weather observations for a station that I would guess counts as "interior" BC.

-Creston

On the 27th, the maximum daily temp occurred at 13:00
On the 28th, the maximum daily temp occurred at 12:00 and 15:00
On the 29th, the maximum daily temp occurred at 14:00
On the 30th, the maximum daily temp occurred at 14:00
On the 31st, the maximum daily temp occurred at 14:00
On the 1st, the maximum daily temp occurred at 14:00
On the 2nd, the maximum daily temp occurred at 11:00 and 12:00
On the 3rd, the maximum daily temp occurred at 14:00

As much as a try to trust a persons observations, it helps to be backed up by some measurements.

A little hint at a reporting station close to you would help verify your "it's warmer at night than during the day" observation.