Your melons won't have the same sweet flavor as they would if they were ripening during a few hot July weeks -- see the link below to the article in the Los Angeles times, "Cantaloupes Need Steady Heat and Sun to Sweeten" -- they'll mature just fine if you pick and store at room temperature (70 to 75 degrees F) for 3 or 4 days, same as you would bananas.
Cantaloupes are sensitive to ethylene gases and can overripen quickly. If you've purchased two or three melons on sale, store them on the kitchen counter, check them daily for ripeness, and refrigerate them as soon as you judge them ready.
Figure that if it was still mid-summer, their fragrance would be a magnet for melon-loving birds, slugs and insects that would damage or destroy them before you ever got to pick them. Worst that can happen is that your fruit will taste the same as it does in the supermarket; most growers pick their melons way before they're ripe enough to eat so they can ship them around the country before they spoil. Sugar production halts once the melons are picked.
Next year, mulch with black plastic to boost soil temperature. You can use this year's melons for seed.