Oh nooo My tomatoes are splitting HELP

I really need help figuring out why my tomatoes are splitting. We're having 100 degree weather right now and we are watering twice a week but our tomatoes are all splitting. Any advice?

Splitting of tomatoes is caused by uneven water availability to the fruit as it ripens, and is greatly exacerbated in very hot weather.We ALWAYS advocate watering EVERY DAY - ESPECIALLY in hot weather! In 100 degree temperatures you should be consideering the need to water TWICE a day.Remember folks, if you are growing in level, ridged beds, it doesn't take much water - only an inch in the narrow 10"-wide growing area.You should also consider giving your tomato plants a little shade in the hottest part of the day. When that sun comes down so strongly on the exposed fruit the temperature changes don't help at all.A 30-50% shade cloth over the plants can give some relief. It may also help your plants continue to set fruit, which is another problem they often experience during the worst of the hot days.