What Time does Sunset Today?
The Short Answer
Sunset occurs when the Sun’s disk is below the horizon, and it varies across the year according to location and time zone. In the Northern Hemisphere, sunset typically occurs around 6 pm local time during the summer months and is slightly earlier during the winter months.
The Science Behind Sunset
Sunset is the daily transition that happens when the upper edge of the Sun’s disk drops below the horizon in the west. It plays an important role in our lives, signaling the end of day and the start of night. But why does sunlight seem to disappear when the Sun is still above the horizon?
The answer lies in the way sunlight interacts with the atmosphere. When sunlight passes through our atmosphere, the light is scattered and broken up into its different component colors. Blue and violet light are preferentially scattered, meaning they don’t make it very far before being deflected in other directions. The longer wavelengths of orange and red light, on the other hand, pass through the atmosphere and reach our eyes.
But when the Sun is too low on the horizon, the atmosphere is thicker, and the blue and violet light is scattered more frequently, reducing the amount of orange and red light that reaches us. This makes the Sun look like it has already set, when in reality it hasn’t, and is the reason why we can sometimes spot the glimmer of what appears to be a “second sunset” in the sky.
How to Calculate Sunset
If you want to know what time it will set in your area, the simplest way is to look it up online. There are plenty of online tools and websites that can tell you what time the Sun will set in your area, based on your current location.
But if you want to calculate the time of sunset yourself, you will need to get access to something called “astronomical twilight”. This is the moment when the Sun is 18° below the horizon, and it signals the start of astronomical night. Breaking it down further, you can use the following equations to calculate the time of sunset for your location:
Sunrise: 6 + (50/60) + (longitude / 15)
Sunset: 18 + (50/60) + (longitude / 15)
The equation will give you a time in Universal Time (UT), which can be converted to local time by subtracting or adding hours depending on which way your time zone is offset from UTC. For example, if you are in the Eastern time zone (UTC-5), you will have to subtract 5 hours from the time you get using the equation.
Conclusion
Sunset is the daily transition where the upper edge of the Sun’s disk drops below the horizon in the west. The time of sunset varies according to location and time zone, but typically it will be around 6 pm in the Northern Hemisphere during the summer months and slightly earlier during the winter months. You can look it up online or use equations to determine the exact time.