At around 9:30 p.m. Mountain Time on Sunday the northern hemisphere was at its greatest angle tilted toward the Sun marking the summer solstice.
Now the northern hemisphere will begin its 6-month treck away from the Sun.
The four seasons on earth are a product of the Earth's tilt, marked by two solstices and two equinoxes.
At the summer solstice when the north pole is tilted toward the Sun, the day lasts longer and the sun appears higher in the sky. This results in warmer average temperatures as additional solar radiation reaches the surface.
In Montana’s winter, the north pole is tilted away from the direct rays of the Sun. The days are shorter and the sun is low in the sky, resulting in cooler temperatures.
Now what if I told you the Earth in its orbit is currently near its farthest distance from the Sun? The orbit is an ellipse, not a circle. At times of the year the earth is closer to the Sun.
Currently, the Earth makes its closest pass to the Sun in the northern hemisphere's winter. So the north is tilted toward the Sun when the Earth is furthest from the sun at the summer solstice. At the winter solstice, the north is tilted away but the planet is closest to the Sun.
This current positioning will change in about 13,000 years when the north pole will be tilted toward the Sun at the Earth's closest pass in summer. At the winter solstice, the north pole will be tilted away from the Sun and be at the farthest distance from the Sun.
This positioning will promote more extreme variation in solar intensity from summer to winter, where theoretically summers will be hotter and winter much colder.
