Select the sentence that is punctuated correctly. even though it is almost summer we still have overcast skies and light rain. even though, it is almost summer we still have overcast skies and light rain. even though it is almost summer, we still have overcast skies and light rain

The last part: even thought it is nearly summer,

The last sentence because "even though" is a transitional phrase. When you begin with a transitional phrase, you always add a comma after beginning the second part of the sentence.

If you read my answer again, you'll see that i put a comma after "when you begin with a transitional phrase". Why? because the word "when" is also a transitional phrase; therefore, a comma is necessary.