I have had lots of blossoms on tomato plants (Big Boy) but no tomatoes yet. Other plants have tomatoes Baltimore, MD
Tomato fruit set is somewhat temperature dependent. Some varieties are more tolerant of extremes in temperature. But others won't set fruit if night temperatures are too cool or too warm. Also, the flowers must be pollinated to set fruit. Normally when grown outdoors, movement caused by the wind is enough to discharge the pollen and lead to fruit set.