Latitude helps determine the temperature of a locale. Since one of the most important factors of climate is the amount of energy, or radiation, received from the Sun (heat), latitude plays a critical role.
Climatologists (people who study climate) use the word insolation for energy that reaches Earth from the Sun. The word combines syllables from the phrase incoming solar radiation. Sunlight is the obvious sign of insolation, but the Sun’s radiation reaches the earth on a cloudy day too. The angle and duration of insolation, which translates into surface temperature, changes depending on latitude.
Because Earth is spherical, when it orbits the Sun, the Sun’s rays hit Earth’s surface directly at the equator and at angles near the poles. Direct insolation is stronger than slanted contact.
Earth also tilts on its axis, so when the Southern Hemisphere is closer to the Sun, it has more hours of daylight than the Northern Hemisphere, and vice versa. At the equator, the hours of night and day remain 12 hours each. But most of us have experienced the shorter days of winter and the longer days of summer that come from Earth rotating at a tilt.
Latitudes that receive direct insolation for many hours a day tend to have warmer climates, such as at the equator. Latitudes toward the North and South Poles get angled insolation for fewer hours overall, and have colder climates.
The longitudinal angle of New York City is 74° west, making the latitudinal and longitudinal coordinates for New York City 40° north and 74° west.