Ready for another New England fall foliage season? Even with a wet weekend thanks to Henri, our forecaster sees the potential for lots of color! Read on for the full New England fall foliage 2021 forecast.
By Jim Salge
Aug 23 2021
I am grateful for this summer’s abundant blackberry crop, which offered a welcome dose of sweetness during a season that was one of the coolest and wettest in recent memory. Fortunately, our thoughts are now turning to autumn, a season with not only beautiful fall foliage but also typically temperate weather.
Fall in New England conjures up an image of clear blue skies, crisp air, cool breezes, and then, beginning in late September, forests changing to an endless tapestry of color. This appealing weather and beautiful landscape provide the background for our region’s spectacular celebrations of the season, with festivals and fairs and tasty treats.
We in the Northeast are fortunate in that our average climate conditions bring about some of the best fall colors in the world. Still, there can be significant variability in the timing, intensity, duration, and hue — and an examination of the weather, climate, and forest factors can help predict how the 2021 foliage season will shape up.
One thing is already clear, though: Some signs of the season are showing up amazingly early. Anywhere that standing water has pooled and ponded this summer, you are likely now seeing red maples and black gums turning blazing bright.
How will this affect the overall New England fall foliage season? As always, it’s a complex question to tackle. Let’s dive in!
Healthy trees and a full canopy of leaves are the first key ingredients for a stellar foliage season, and their story actually begins the previous winter, when the buds were formed and dormant.
New England’s past winter was an odd one. Mid-December saw the heaviest snowfall, a historic dumping of the white stuff that was measured in feet — as many as four feet all at once! But while skiers were thrilled at the prospect of starting off their season with a massive base, that enthusiasm was washed away on Christmas Day: Temperatures rose above 60 degrees, rain poured down, and the snowpack vanished.
Nationwide, the major weather storylines of last winter were marked by massive cold snaps and images of busted pipes and indoor icicles all the way to the Gulf of Mexico. New England, however, remained largely warmer than normal. Outside of its high mountains, it never received another major snowfall, and most areas didn’t see even a single snowflake in March.
The forests of New England rely on a slowly melting snowpack to deeply wet the soils and water the trees in advance of springtime leaf-out. But by April Fool’s Day, it had all largely melted. A surprise snowstorm in mid-April didn’t do much to abate the dry conditions, and there was little rainfall all the way through June. Leaves arrived on time but were perhaps a bit small and thin this year.
Then, in July, it started raining.
Even without any tropical systems in play, July ended as one of New England’s top five wettest months ever, period. In Concord, New Hampshire, it rained on 24 of the 31 days in July. Ten to 15 inches of rain fell regionwide, and in some places close to 20. July was also abnormally cool, breaking our streak of months with above-average temperatures. (Random weather fact of the year, or maybe the decade: Augusta, Maine, was warmer last Christmas than it was this past Fourth of July.)
All that rainfall caused trees to move from drought-stressed to overwatered. Many red maples in swamps and wetlands began turning color as early as August — but don’t worry, these trees can hold their leaves for a long time, perhaps even until the big show begins, so these early signs in wetlands will be a long and beautiful preview this year.
There was one big exception to this summer’s weather pattern: The far northern tier of New England, right along the Canadian border, where the leaves turn first, missed out on most of the rain (more on that later). Generally, though, as I write this 2021 fall foliage outlook, the soils are soaked and, even though the weather has turned slightly drier and warmer, hints of autumn abound.
Any New Englander who’s spent time in the woods recently, or even their backyard, knows that this has been a banner year for mushrooms. Across the region, fungi of all types have transformed the forest floor into a rainbow of colors. And while mushrooms don’t have any effect on the foliage, they can give insight into other forest conditions.
One type of leaf fungus that we look out for every year is anthracnose, which sets up in the spring and can really impact fall color. Because of the dry start to the year, it seemed likely anthracnose would not be much of a concern, but July proved so wet that it crept back in. So far it seems to be affecting only oak trees, but it bears watching.
By contrast, the dry spring set up perfect conditions for the LDD moth (aka Lymantria dispar dispar, formerly known as the gypsy moth), since the main natural defense against this invasive pest is a fungus that can’t spread when it’s dry. As a result, northern New England saw its biggest outbreak of LDD moths in more than 30 years, with areas of impact reported all across that region. But fear not, leaf peepers: While we’ve seen whole hillsides defoliated this summer, adjacent areas have been left untouched, so you will be able to explore around the affected areas this fall.
Since trees expend a lot of energy putting out flowers and seeds, aka mast, they don’t produce heavy crops every single year. When they do, though, it can make for a thinner forest canopy. After two oak “mast years” in a row (which incidentally caused the chipmunk population to explode), most oak trees are having an average year in 2021. Additionally, maples have had an average to light year. So while the leaf canopies for these species may be a bit thin from the drought, they were not deprived of much energy by seed-making.
But it’s a different story for beech and black gum trees, which are having a banner year for mast. Beeches, especially, are important to the fall foliage display, as they hold on to their color after many other species have dropped their leaves, so we do see some potential for diminished late-season color this year.
Even with a good setup for leaf growth, the best foliage color can occur only if the autumn weather cooperates. Warm, sunny days and crisp, cool nights will accelerate the fading of green chlorophyll while also sparking the formation of red pigments, which are produced in the fall as a sort of sunscreen for the transforming leaves.
The weather patterns shaping up for this fall look promising for a beautiful and classic show. The earth is set to move into a slight La Niña pattern before winter, which tends to keep New England’s weather active, wet, and warm, yet also provides opportunities for strong cold fronts to clear things out. Given the healthy mix that is typical in La Niña years of cool weather battling it out with warm and wet, we remain optimistic.
One possible downside to La Niña, though: It can steer systems close to New England. Tropical Storms Fred and Henri have already made headlines in 2021, with Henri posing the largest threat over the weekend. Thankfully, it weakened quickly, sparing widespread wind damage. We’ll be keeping an eye on the busy Tropical Atlantic before our September update, as a strong storm can definitely affect the forests before fall.
Putting all this information together, we see a forest that, despite a dry, thin, and stressful start to its season, is largely well-watered as it heads toward fall. This isn’t true in all areas, though, and that distinction may lead to two foliage setups. So we need to break the 2021 fall forecast into the far north and then the rest of New England.
Near the Canadian border, spring was dry and summer rains failed to ease the drought. Even if there are warm and wet periods this fall, strong cold fronts and cool breaks will likely cause these dry forests to turn earlier than usual. This means that a bright punch of vibrant but short-lived color should arrive across New England’s northern tier in late September.
Farther south, the setup for autumn remains encouraging, despite the pockets of insect damage and a lingering potential for rainfall-fed fungus growth. Generally, fall color tends to last longer after a wet summer; combining that with a forecast for continued warmth, we expect a season that is either on time or later than historical averages. This means that the wave of peak color will slide south and to the coast over the course of October.
Again, the exceptions to this are the wetland areas, where red maples and black gum are already changing and will turn brightly. A September canoe trip could yield terrific isolated early color in many places across New England.
The key for this season will be flexibility.
Things to look for in our mid-September update:
1) Whether continued rain will bring more leaf fungus and mildew, dulling colors
2) Whether the tropics will continue to be active, steering storms over New England
3) Whether the pattern will shift briefly but intensely cold in the weeks before peak, moving the timeline up
Hoping to make the most of foliage season this year? We’re here to help you plan your visit and keep up with the changing colors. Check out our peak foliage map, plan a perfect fall road trip, and stay tuned for weekly “where to see peak foliage now” posts starting next month.
We can’t wait to share the season with you!
While New York state got a lot of rain this summer, there was less precipitation as you moved south into the mid-Atlantic. There, a generally hot and seasonably dry summer, and the expectation for above-normal temperatures into fall, should lead to autumn colors that are later than normal, brief, and abruptly bright. But foliage in New York state, especially the Catskills, should be timely, bright, and beautiful.
Drought is a concern in the southern Appalachians, an area known for its foliage display. Autumn rainfall is predicted to be above normal, but the temperatures are too — so there are conflicting factors at play. Stick with historical average peak times here, but be prepared for a brief show.
The Great Lakes region has little drought, and the spring and summer setup has been good for forest health. We expect a banner foliage year in states like Wisconsin and Michigan, with the western drought being more of a concern in Minnesota.
Much of the Mountain West has been hot and dry, which should make for an early and brief color show. The pick of the region is eastern Colorado, which is drought-free and could see a great year for aspens.
The Pacific Northwest has had a summer that’s so far outside its climate averages, it’s hard to predict what the autumn show will look like, to be honest. In an unusual year, the safe bet might be a trip to see an unusual tree, and we love the golden larches in the mountains away from the coast.
This post was first published on August 19 and has been updated.