Tuesday is the spring equinox. What does that mean? Will Washington enjoy more daylight?
Washington’s short winter days are turning into long summer ones, and quickly.
The days have been getting longer since the winter solstice, and they’ll continue to do so until the summer solstice in June. But the rate at which they get longer peaks between the two at the spring equinox, which arrived Tuesday.
Days get longer at faster rates in March
Since the Earth’s axis is at a slight tilt, the Northern Hemisphere is pointed closer to the sun during our summer months, and the Southern Hemisphere is pointed closer to it during our winter. According to Jacob DeFlitch, a meteorologist at the Seattle-Tacoma branch of the National Weather Service, as the Northern Hemisphere begins to tilt more and more towards the sun, days get longer at an increasing rate.
“What happens is the Earth is tilted more towards the sun during these times. So we’re leaning to more daylight during this period, which is why we’re seeing an additional little under two hours through the month of March,” DeFlitch told McClatchy News in a phone interview.
The rate at which they increase isn’t steady, though. The days on either end of the equinox see the starkest increase. While days will still get longer, the rate of increase will start going down until we hit the summer solstice, when it slows to a halt. DeFlitch said that this is due to the shape of the Earth’s orbit.
“The Earth generally moves in an ellipse around the sun, so there’s going to be different rates of increasing and decreasing sunlight during the spring and autumn seasons,” DeFlitch said.
How much daylight does Washington gain?
In Tacoma, the sun rose at 6:48 a.m. on March 1 and set at 5:55 p.m., for a total of 11 hours and seven minutes of sunlight. On the 31st, after the clocks were moved ahead by an hour, it’s expected to rise at 6:49 a.m. and set at 7:38 p.m., for nearly 12 hours and 50 minutes of sunlight. That’s a one-hour, 43-minute gain in one month and three minutes, 24 seconds on a typical day. Olympia’s numbers were nearly identical, with a monthly increase of over an hour and 41 minutes.
In the Tri-Cities area, meanwhile, there were 11 hours and nine minutes of sunlight on the first and a projected 12 hours and 48 minutes on the 31st. The area saw an increase of three minutes and 16 seconds in March.
Northern Washington has the starkest increase in the state. Bellingham started the month with 11 hours, four minutes of daylight and is expected to end it with a 12-hour, 52-minute day, which amounts to an average of a three-minute, 35-second gain daily.
Parts of the state further south will still see an increase in daylight in April, it just won’t be quite as stark. Tacoma is expected to gain an hour and 34 minutes of daylight next month, while Bellingham will gain an hour, 39 minutes and the Tri-Cities will gain an hour and a half.
