Jerry,
You are right that tomato plants grow profusely in hot weather.....But, during extended periods where daytime temperatures exceed 90 degrees F and nightime temperatures exceed 80 defrees F, tomato pollen efficacy is compromised and blooms may fall off producing no fruit. In fact, at temperatures over 100 F, tomato pollen dies. The effect of this is that 60 to 70 days after period of extreme heat that might last for two weeks you may experience a couple of weeks of very few ripe tomatoes, with the harvest picking up again afterwards.