You can't let the warm sunny days in early May fool you into planting outside too early. Even though it is 70 degrees F outside as I am writing this. The 24 hour Temperature Graph below tells the real story... The red line is the temperature outside and the blue line is inside my heated greenhouse. The minimum outdoor temperature was 27.7 degrees F at 5:48 AM on Friday morning May 9th - and tender plants would suffer frost damage if they were planted outside unprotected. My heated greenhouse never went below 44 Degrees F. Hardy plants like kale or broccoli would probably be okay outside, but unprotected tomatoes and peppers would be likely to show some damage from cold stress and probably some frost damaged leaves. It is still very possible to get another hard freeze for the next few weeks and it is simply not worth the risk. The micro climate in my yard happens to be 5 to 10 degrees colder than the official weather data from the local airport weather station just 3 miles away. My home weather station has really helped me to know what is going on in my garden.