Most of the warm-season vegetables we grow are native to tropical and subtropical climates. They thrive best during hot, humid weather.
Although Colorado summer days are generally hot, our nights aren't. Low humidity allows the temperatures to drop at night. We like that but most tropical plants don't.
So if your heat-loving tomatoes are slow to ripen this year, blame the cool spells and cool nights. The fruit will eventually ripen but have patience. Please don't follow misguided advice to force them to ripen by withholding water. You end up with dying plants and dry, tasteless tomatoes.
Peppers have performed better than expected despite the lack of heat. Consider growing the green pepper 'Big Bertha,' which is living up to its name.
Bush beans got off to a slow start but have made up for lost time. The key to keeping them producing prolifically is to keep them picked. This encourages the plants to keep blooming.
Cabbage has had a great year. As the heads form, pick them before they crack. Cut the head off at the base and remove the outer leaves. The variety 'Stone Head' produces a very thick, dense head and is one of the varieties that matures early. Red cabbage matures later.
Other crops such as cucumbers, squash and eggplants are having decent yields. Keep them well-irrigated and pick them as they ripen. Almost all vegetables except tomatoes should be refrigerated to keep them from dehydrating. There is still plenty of time for your vegetables to mature. Be patient.