My Personal Weather Station

Weather at Boston, Logan International Airport, MA - via NOAA's National Weather Service

Current Watches, Warnings and Advisories for Massachusetts Issued by the National Weather Service

Monday, June 20, 2011

Summer Sunsets- A story of Time

With the first day of summer tomorrow, lets take a look at the longest day of the year in terms of sunsets across the country.

In the days prior to the railroad, time was all local. The time in Boston was different than the time in New York, or for that matter even in Worcester.  With the advent of railroad transportation and a need for accurate schedules between destinations, a uniform time was needed. This is when time zones were created. Now all towns in a certain zone would be the same exact time.



With the tilt of the earth on an axis of 23.5 degrees, the northern pole is facing the sun on the Summer Solstice.  So areas further north of the equator (which always has equal daylight) get more daylight and above the Arctic Circle, it is 24 hours of daylight. If you are a fan of longer daylight at night, the best places to live are north and west in a time zone.



Sunsets for areas in New England on the Summer Solstice


Nantucket, MA has the earliest sunset in all of New England, but areas further east like Fort Kent, Maine have a later sunset, due to the tilt of the axis of the earth and the increase in daylight the further north. (the opposite is true in Winter)

The map shows sunsets based on  Eastern Daylight Time Zone (EDT).

The earliest sunrise in the country is Van Buren, Maine at 4:36 AM (despite Eastport, Maine's claim of the earliest sunrise in the country, it is only true from mid August to late April)


Sunset across the U.S. on the Summer Solstice. 

I always wondered where would one want to live to have the longest daylight possible and who has the shortest.

(all times are respective of their correct time zones)
On the east coast, Miami, FL & Nantucket, MA have the earliest sunsets.

West Chattahoochee, FL has the earliest sunset in CDT at 7:45 PM.


The earliest sunset for the entire country is in southeast Arizona, (which does not observe Daylight Saving Time) at 7:24 PM MST


The latest sunsets in the country, if you want to have plenty of daylight to do outside activities are Isle Royale National Park, Michigan at 9:59 EDT and the border in Montana, North Dakota and Saskatchewan at 10:04 PM CDT


**Alaska has later times, but not included here.




Solar Noon

Prior to the time zone, every town based their time on solar noon, when the sun was the highest in the sky that day( true noon), it would be noon and everyone in that town would set their clock to this time.  

Solar noon can still be used today if you have a sun dial. An example today would be today in Boston solar noon would be at 12:45:59 PM EDTand in Worcester solar noon is at 12:48:53 PM EDT (New York - 12:57 PM EDT and South Bend, IN  - 1:46 PM EDT)

Or there is roughly a 1 minute difference for every 12.5 miles of distance.



No comments:

Post a Comment