equinox - RVing with Rex

Autumn has caught us in our summer wear.
—Philip Larkin, British poet (1922–86)

It’s officially the last day of summer which means that pumpkin spice and sweater weather are basically upon us. Rather than bemoan the end of one season, I’m looking forward to everything autumn brings with it—including crisp morning air and apple cider. Consider today’s post your fall kickoff complete with a leaf-peeping guide and some great road trips for the season.

Saying farewell to the long, warm days of summer can be bittersweet but the sheer majesty of the changing fall foliage makes the transition a little bit easier. As autumn’s cooler temperatures and shorter days set the trees ablaze with color, now is an ideal time to plan a leaf-peeping road trip, hike, or other excursion to take in the views.

It is the summer’s great last heat,
It is the fall’s first chill: They meet.
—Sarah Morgan Bryan Piatt

Blue Ridge Parkway *© Rex Vogel, all rights reserved*

The fall season officially begins on Saturday, September 23. This date marks the autumn equinox or the date between the summer and winter solstices when day and night are nearly equal lengths. (We also know it as the first day of the year when you can order a pumpkin spice latte with no shame.)

During an equinox, the Sun crosses what we call the celestial equator—an imaginary extension of Earth’s equator line into space. The equinox occurs precisely when the Sun’s center passes through this line.

After the autumnal equinox, days become shorter than nights as the Sun continues to rise later and nightfall arrives earlier. This ends with the winter solstice after which days start to grow longer once again.

The word equinox comes from Latin aequus, meaning “equal” and nox, the Latin word for “night.” On the equinox, day and night are roughly equal in length.

Great Smoky Mountains National Park *© Rex Vogel, all rights reserved*

But why do leaves change color in the fall?

Autumnal leaves in vibrant hues are a beautiful part of the season but those leaves are also a vital part of keeping trees alive. The trees with leaves that change color in fall are deciduous. (Evergreen trees with needles which stay green to continue the photosynthesis process through the winter are coniferous.) Deciduous trees usually have large, broad leaves.

Most of the year, these leaves are green because of the chlorophyll they use to absorb energy from sunlight during photosynthesis. The leaves convert the energy into sugars to feed the tree.

As the season changes, temperatures drop and days get shorter. Trees receive less direct sunlight and the chlorophyll in the leaves breaks down.

The lack of chlorophyll reveals yellow and orange pigments that were already in the leaves but masked during the warmer months. Darker red leaves are the result of a chemical change: Sugars that can get trapped in the leaves produce new pigments (called anthocyanins) that weren’t part of the leaf in the growing season. Some trees like oaks and dogwoods are likely to produce red leaves.

Vermont *© Rex Vogel, all rights reserved*

When do fall leaves change color

Leaves can change their color from as early as mid-September through early November. Typically, the second and third weeks of October are the peak times but it shifts depending on your location and your local weather conditions.

Foliage starts to change in the northern-tier states out West and in the Midwest by late September. By October 2, the leaves in some areas will be past their prime.

Much of New England as well as the Pacific Northwest will be at or near peak fall color by October 9.

A little further south in the Blue Ridge Mountains, mid-October is your best bet.

Cherohala Skyway, North Carolina/Tennessee *© Rex Vogel, all rights reserved*

See below for times of the year of peak foliage around the country:

Oregon: Best viewed while driving along scenic highways from mid-September through mid-October; however, color conditions vary daily based on humidity and fog density.
North Carolina: North Carolina’s leaf patterns move east across the state. The first leaves in the western part of the state begin to peak the week of October 9. By October 23, the entire state should peak and the show will be pretty much over by November 1.
Vermont: Optimal viewing from September 18 through October 2 although the leaves will begin to change in early September.
New Hampshire: Leaves in New Hampshire will be at their best the last week of September. By October 16 most of the state will have changed.
Washington: Washington State leaves normally hit their peak the week of October 9 and past their peak by October 23.

Shenandoah National Park *© Rex Vogel, all rights reserved*

Top destinations for viewing fall leaves

Here is a list of my picks for the most idyllic spots in the U.S. for viewing fall leaves. Some are off the beaten path, some are on more popular, scenic routes for you to enjoy whether on foot or by vehicle. I’ve also included the dates for peak foliage viewing for each location.

Skyline Drive, Shenandoah National Park, Virginia

Peak Viewing: October 9-28

Virginia’s Skyline Drive is a National Scenic Byway that runs 105 miles along the crest of the Blue Ridge Mountains. The speed limit is 35 mph with 75 overlooks to pull over and enjoy the sights of the Shenandoah Valley below. Often called one of America’s favorite mountain drives, Skyline Drive is “good for the soul.”

La Sal Mountain Scenic Loop *© Rex Vogel, all rights reserved*

Moab, Utah

Peak viewing: Mid September to mid October

Aside from aspens, cottonwoods, and other deciduous trees making the slow turn to brilliance, the abundant sandstone rocks change colors here, too. Shorter days and angled fall light combine to give Moab’s signature sandstone deeper, more varied colors than usual. Several different leaf-peeping routes include the La Sal Mountain Loop Road Scenic Backway, the Gemini Bridges Trail, the Poison Spider Mesa Trail, and the Moab Rim Trail. Jeeps are required on all routes except the La Sal

Great Smoky Mountain National Park, North Carolina and Tennessee

Peak viewing: Mid to late October, depending on elevation.

You’d be hard-pressed to find any terrain more perfectly orchestrated for fall color viewing than the Great Smoky Mountains. Lots of sumac adds to the brilliant reds but the Park boasts an amazing diversity of trees and terrain that add to the color spectrum—some 100 species of native trees live in the Smokies. To enjoy them, drive the Clingmans Dome Road, the Blue Ridge Parkway, or the Foothills Parkway.

Mount Washington Cog Railway, New Hampshire *© Rex Vogel, all rights reserved*

Kancamagus Scenic Highway, Lincoln, New Hampshire

Peak viewing: September 25-October 7

The Kancamagus Scenic Highway in the White Mountains of New Hampshire known by the locals as The Kanc provides some of the most spectacular fall foliage viewing in New England. The Kanc’s 35-mile scenic pass that connects Lincoln to Conway (Route 112) has some tricky hairpin turns and no gas stations so be prepared. It does have plenty of places to pull over and enjoy the grandeur of the vistas.

Julian apples *© Rex Vogel, all rights reserved*

Julian, California

Peak viewing: Early to mid-November.

In Julian, autumn is the grandstand season both for apple-pie eating and leaf-peeping. Sample the town’s homemade apple confections then watch black oaks do their color-changing trick at Lake Cuyamaca in Cuyamaca Rancho State Park. A scenic 45-minute drive leads to Palomar Mountain State Park where you can put some miles on your feet while you admire bracken ferns and leafy oaks on the Thunder Ridge and Chimney Flat Loop. Or hike the Five Oaks Trail at Volcan Mountain Wilderness Preserve, home to some of the oldest and largest black oaks in San Diego County.

Worth Pondering…

It’s the first day of autumn! A time of hot chocolatey mornings, and toasty marshmallow evenings, and, best of all, leaping into leaves!

—A. A. Milne

The first day of spring is Monday, March 20, 2023, at 5:24 p.m. EDT. For those of us in the Northern Hemisphere, this was marked by the arrival of the Vernal Equinox (otherwise known as the First Point of Aries). Vernal translates to new and fresh and equinox derived from the Latin aequus (equal) and nox (night).

When does spring start? *© Rex Vogel, all rights reserved*

Every year, weather forecasters welcome the arrival of spring on the first day of March—while others contend that the spring really begins a few weeks later with the equinox which falls on or around March 21. So who is right about when the seasons begin and end?

It depends on why you’re asking. Seasons are defined in two ways: astronomical seasons which are based on Earth’s position as it rotates around the sun and meteorological seasons which are based on annual temperature cycles. Both divide the year into spring, summer, fall, and winter—yet with slightly different start and end dates for each. Here’s what they mean and how to tell them apart.

Astronomical seasons

People have used observable periodic natural phenomena to mark time for thousands of years. The natural rotation of Earth around the sun forms the basis for the astronomical calendar in which we define seasons with two solstices and two equinoxes. Earth’s tilt and the sun’s alignment over the equator determine both the solstices and equinoxes.

Ancient Rome was the first to officially mark those seasons with the introduction of the Julian calendar. Back then, the seasons began on different days than the modern era because of discrepancies with the Gregorian calendar used primarily today. Now, the start of each astronomical season is marked by either an equinox or a solstice.

The equinoxes mark the times when the sun passes directly above the equator. In the Northern Hemisphere, the summer solstice falls on or around June 21, the winter solstice on or around December 22, the vernal or spring equinox on or around March 21, and the autumnal equinox on or around September 22. These seasons are reversed but begin on the same dates in the Southern Hemisphere.

Solstices mark the brightest and darkest days of the year. They are also driven by Earth’s tilt and mark the beginning of astronomical summer and winter. When the Northern Hemisphere is tilted toward the sun, it is brighter and feels like summer while at the same time the Southern Hemisphere is tilted away from the sun, plunging it into a dark winter.

Because Earth actually travels around the sun in 365.24 days, an extra day is needed every fourth year creating what we know as Leap Year. This also causes the exact date of the solstices and equinoxes to vary. Additionally, the elliptical shape of Earth’s orbit around the sun causes the lengths of the astronomical seasons to vary between 89 and 93 days. These variations in season length and season start would make it very difficult to consistently compare climatological statistics for a particular season from one year to the next. Thus, the meteorological seasons were born.

Meteorological seasons

Since at least the 18^th century, scientists have sought better methods of predicting growing seasons and other weather phenomena. Over time, that gave rise to the concept of meteorological seasons which are more closely aligned with both annual temperatures and the civil calendar.

Meteorological seasons are far simpler than astronomical seasons. They divide the calendar year into four seasons that each last exactly three months and are based on the annual temperature cycle. Winter takes place during the coldest three months of the year, summer in the hottest three months, and spring and fall mark the remaining transition months.

In the Northern Hemisphere that means the start date for each season is March 1 (spring), June 1 (summer), September 1 (fall), and December 1 (winter). In the Southern Hemisphere the seasons are reversed; spring begins in September, summer in December, fall in March, and winter in June.

Meteorological observing and forecasting led to the creation of these seasons and they are more closely tied to our monthly civil calendar than the astronomical seasons are. The length of the meteorological seasons is also more consistent ranging from 90 days for winter of a non-leap year to 92 days for spring and summer. By following the civil calendar and having less variation in season length and season start, it becomes much easier to calculate seasonal statistics from the monthly statistics, both of which are very useful for agriculture, commerce, and a variety of other purposes.

The consistency of meteorological seasons allows meteorologists to make the complex statistical calculations necessary to make predictions and compare seasons to one another. “Dealing with whole-month chunks of data rather than fractions of months was more economical and made more sense,” climatologist Derek Arndt told the Washington Post in 2014. “We organize our lives more around months than astronomical seasons, so our information follows suit.”

So when is the first day of spring? It isn’t March 1 or the spring equinox—it’s both.

But, if you live in Canada or the northern states you may argue, as I do, that we need a third means of determining the first day of spring. I suggest that spring really begins with the appearance of the first tiny leaves on the trees or the first crocus plants peeping through the snow? The First Leaf and First Bloom Indices are synthetic measures of these early season events in plants, based on recent temperature conditions. These models allow us to track the progression of spring onset across the country.

Take a look outside. If the birds are chirping, tree leaves are budding, the grass is turning green again—then it is spring!

>> DIG DEEPER

Worth Pondering…

She turned to the sunlight

And shook her yellow head,

And whispered to her neighbor: Winter is dead.

—A.A. Milne, When We Were Very Young

Tag: equinox

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