During the summer solstice, the Earth is positioned so that the Northern Hemisphere is tilted at its maximum angle towards the sun. This means that the North Pole is tilted closest to the sun.

Here's a breakdown:

* Earth's Tilt: Earth's axis is tilted at approximately 23.5 degrees. This tilt is the reason we have seasons.

* Summer Solstice: On the summer solstice, the Northern Hemisphere is tilted at its maximum 23.5 degrees towards the sun. This happens around June 20th or 21st in the Northern Hemisphere.

* Sun's Rays: The sun's rays strike the Northern Hemisphere at a more direct angle, resulting in longer days and warmer temperatures.

* 90 Degree Angle: The sun's rays strike at a 90 degree angle (directly overhead) at the Tropic of Cancer, which is located at approximately 23.5 degrees north latitude. This is the farthest north the sun's rays can directly hit.

Important Note: While the Northern Hemisphere experiences summer during the summer solstice, the Southern Hemisphere experiences winter. This is because the Southern Hemisphere is tilted away from the sun at this time.