Denise Goldberg's blog

Tuesday, September 14, 2010

Daylight hours

I was chatting with a colleague this morning when I mentioned how much I have noticed the difference in the amount of daylight here in comparison with Iceland. He reminded me that we are very close to the equinox, the day of equal light and dark, the same characteristics here and in Iceland. The late sun rising earlier sun setting really hit me when I returned home though; all I could figure was that the sunrise in Iceland was earlier.

When I got home tonight I decided it was worth a look for a sunrise-sunset table for Iceland for the month of September. What I found was very interesting. I found a sunrise sunset table for Boston on the National Weather Service website on a page titled Sunrise & Sunset or Moonrise & Moonset plus other data. I found sunrise and sunset times for Reykjavik at I looked at the month of September for both locations.

On September 1st, Boston had the possibility of sunlight for 13 hours and 9 minutes. The daylight time each day decreases by about 2 1/2 minutes until a 12 hour day is reached on September 25th.

On September 1st in Reykjavik, sunrise was at 6:11 with sunset at 20:43 for a day of 14 hours and 32 minutes. Unlike the 2 1/2 minute stepdown day by day at the lower latitude, the daylight decreases by 6 to 7 minutes each day until reaching the equinox.

No wonder I noticed the difference. On my last full day in Iceland, daylight filled 13 hours and 33 minutes. On my first full day at home, there were 12 hours and 38 minutes of daylight. I know, it's only an hour, but it was noticeable.