TOWSON, Maryland, Monday, June 26 and Saturday, June 24, 2017 - It is hard to fathom on a warm June Saturday, but the longest day of 2017 has now come and gone, and the days here in Baltimore and everywhere else in the Northern Hemisphere already grow shorter.
Conversely, the nights grow longer. Sooner than you think, longer nights will mean cooler nights because when the sun is below the horizon, heat escapes the earth's surface and radiates8jus off into space. The longer the sun is "down," the more heat that is able to escape.
A few days of cool weather here in Baltimore proves the point. Forecasters say that temperatures will not reach 80 degrees on Tuesday and will fall into the 50's on Tuesday Night. It all sounds good to me. Looking further down the road, forecasters say that temperatures will warm toward the end of the week before cooling off again on Sunday and early next week.
According to data available at the United States Naval Observatory in Washington, D.C., , sunrise in Baltimore on Tuesday, June 20 was at 5:40 am, and sunset was at 8:36 pm. All times I have provided are in Eastern Daylight Savings Time computations. Subtract an hour from any reading to obtain the Eastern Standard Time computation.
Somewhat surprisingly - at least to an amateur like me - the sunrise and sunset in Baltimore were exactly the same on June 18, 19 and 20. On June 21, the sunrise remained the same - 5:40 am - but the sunset was one minute later at 8:37 pm. Sunrise is at 5:40 am in Baltimore from June 18 through June 22. The Summer Solstice for this year, in the entire Northern Hemisphere, was at exactly 24 minutes past midnight on June 21. After the Solstice, we know that, however slowly, the days begin to shorten and the nights begin to lengthen.
Near the date of the summer solstice, the length of days changes slowly. Beginning on June 23 (yesterday), the sun rose one minute later, at 5:41 pm., for three straight days.
The change in the sunset is even slower. From June 17 through June 20, the sun dropped below the horizon at 8:36 pm. On June 21, the very day that the solstice occurred, the sun went down one minute later, at 8:37 pm. The sun continues to set at 8:37 pm until the day before the Fourth of July celebration. That is a streak of 13 straight days. From July 4 through July 7. the sun returns to a setting time of 8:36 pm. Then, on July 8. it sets at 8:35 pm.
Not many people realize that sunrise and sunset change as you travel north and south, even within the United States.
Hence, at Bar Harbor, Maine, the Sunrise on June 21 was at 4:49 am, while sunset was at 8:21 pm
If you do the math, the sun rose in Maine some 51 minutes sooner than it did in Baltimore. But the sun went down in Maine 16 minutes sooner than in Baltimore (Bar Harbor Sunset was at 8:21 pm; in Baltimore it was at 8:37 pm).
If you went south from Baltimore to Miami, Florida, the changes in the sun's time above the horizon are even more dramatic. Sunrise in Miami on June 21 was at 6:30 am, and sunset was at 8:15 pm Thus, on June 21, the sun rose in Bar Harbor, Maine at 4:49 am, in Baltimore at 5:40 am, and in Miami at 6:30 am. The difference in sunset is less dramatic. On June 21, the sun went below the horizon in Bar Harbor at 8:21 pm, at Baltimore at 8:37 pm, and at Miami at 8:15 pm. Don't expect me to explain this difference to you.
For the heck of it, I checked the sunrise and sunset across the Atlantic in London. On June 21, the sun rose in London at 4:43 am and went below the Horizon at 9:21 pm. In Krakow, Poland, the sun came above the horizon at 4:30 am and went below the horizon at 8:53 pm. The source I used for the Krakow data is "timeanddate.com". The web page notes that it never gets completely dark in Krakow at this time of year. The site notes, "Today it does not get darker than Astronomical Twilight." in Krakow.
The ten day forecast in Krakow is pretty typical for that beautiful city. There is one unusually warm day in the forecast - Wednesday, June 28 is supposed to have a high temperature of 89 degrees and a low of 70 degrees - and lots of cooler days that make a person like me quite envious. Today - and remember that Krakow is six hours ahead of Baltimore - the high is supposed to be 78 and the low 57. After three days with highs in the 80's, the thermometer is back down in the 70's for highs and the 50's for lows for the rest of the forecast period, save for Friday, July 7, when the high is predicted to be 82 and the low 58.
The weather in London is predicted to be even cooler and, not surprisingly, wetter. The ten day forecast for the environs of the upper Thames River finds "high" temperatures frequently failing to hit 70 degrees (4 of the first 5 days of the period) and lows always (always!) in the fifties. As for precipitation, on 9 days of the forecast period, rain chances are 30% or higher. Only once in the forecast period is the London humidity predicted to be under 50%, and that is today. By comparison, the Krakow humidity forecast calls for humidity readings below 60% everyday during the period except today.
I like these two European forecasts. Am I allowed to say this?
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