Santa has nothing on city parks: a new study finds that visiting one can make you as happy as you feel on the happiest day of the year: Christmas.

Santa Claus has long been known as the world’s biggest spreader of happiness and joy, but he now has some competition when it comes to eliciting smiles on Christmas Day. Recent research shows that a visit to a city park can lift your mood up to the same kind of highs as those you experience on December 25.

On the social media platform Twitter, the happiest day each year is Christmas. So, for a three-month span, scientists from the University of Vermont studied hundreds of “tweets” (short messages) that people posted on Twitter from 160 parks located in San Francisco. They found that those in the parks used happier words and expressed less negativity than they did before their excursions into outposts of urban nature. What’s more, the elevated moods lasted, like a glow, for up to four hours. In fact, the effect was so strong that it was equivalent to the mood spike on Christmas.

Published on August 19, 2019, in People and Nature, an open-access journal of the British Ecological Society, the study showed that the strongest positive effects came from visits to large, regional parks that have a lot of tree cover and vegetation. In smaller, neighborhood parks, there was a smaller spike in people’s moods. The least lift came from civic plazas and squares that are mostly paved.


Visits to large, regional parks that have a lot of tree cover and vegetation—such as New York City’s Central Park—provided the strongest positive effects in lifting moods.

Now, with more people living in cities, growing rates of mood disorders and coronavirus pandemic stress, this research may have powerful implications for public health and urban planning.

Measuring happiness

To measure happiness, scientists in the recent study relied on what’s called a hedonometer. This online instrument has been gathering and analyzing billions of tweets for more than a decade, and its data has resulted in numerous scientific papers and global media coverage. The instrument uses a body of about 10,000 common words that have been scored by a large pool of volunteers for what the scientists call their “psychological valence,” a measure of each word’s emotional temperature.

The volunteers ranked words they perceived as the happiest near the top of a one-to-nine measurement scale; sad words were grouped near the bottom. Averaging the volunteers’ responses, each word received a score: for example, happy ranked 8.30, ha ha received 7.94, flowers got 7.56 and parks scored 7.14. Truly neutral words, such as and and the, measured 5.22 and 4.98, respectively. At the bottom, trapped achieved a rank of 3.08, crash earned 2.60 and jail got 1.76.


One of the words that shows the biggest gain in use in tweets from parks is “flowers,” a term that garners a pleasant 7.56 on a nine-point scale.

The researchers analyzed tweets from 4,688 users who publicly identified their location and whose messages were geotagged with latitude and longitude as being in the city of San Francisco. Then, working with the U.S. Forest Service, they developed some new techniques for mapping vegetation of urban areas at a very detailed resolution—about a thousand times more precise than previously existing methods.

What the scientists discovered was that negative language—words such as not, no, don’t and can’t—decreased in the period immediately after visits to urban parks, offering specific linguistic markers for the mood boost available when outside. Overall, the tweets posted from the urban parks in San Francisco were happier by a dramatic 0.23 points on the hedonometer scale over the baseline—an increase in sentiment equivalent to that of Christmas Day for Twitter as a whole in the same year.

Additionally, the researchers found that it’s not just getting out of work or being outside that brings the biggest positive boost: the greener the park is with trees and vegetation, the happier and less self-absorbed people feel. They noted that one of the words that shows the biggest uptick in use in tweets from parks is flowers.


The greener the park is with trees and vegetation, the happier and less self-absorbed people feel.

Conversely, the study demonstrated that the use of first-person pronouns—I and me—drops off dramatically in parks, perhaps indicating “a shift from [an] individual to [a] collective mental frame,” the scientists write. In other words, egoism tended to fall.

Some might argue that Twitter users are not a representative sample of all people. Still, earlier research shows that Twitter users are a broad demographic (on some subjects, the views of Twitter users are not dramatically different from those expressed by all U.S. adults), and this approach to near-real-time, remote sensing via Twitter posts—not based on self-reporting—offers a new window into the shifting moods of very large groups of people.

Yearning for growing green spaces

According to the hedonometer, emotions expressed online started trending lower in mid-March 2020 as the impacts of the coronavirus pandemic began to hit us hard. As lockdowns continued, the lowest sentiment scores on record were registered.


The researchers examined tweets from more than 4,000 Twitter users whose messages were geotagged as coming from San Francisco parks, such as Mission Dolores Park.

Recent surveys of park visitors have shown that people have been using green spaces more since the COVID-19 lockdowns began. Many people reported that parks were highly important to their well-being during the pandemic. It’s clear we need more urban parks.

Although it isn’t easy to create new parks on the scale of San Francisco’s Golden Gate Park or New York City’s Central Park, smaller projects can expand outdoor green spaces. And, luckily, these initiatives don’t have to be expensive. In a University of Pennsylvania study, for example, renovating a vacant lot by removing trash, planting grass and trees, and installing a low fence cost only about $1,600.

Cities can also create parklike areas by closing streets to cars. Many cities worldwide are currently retooling their transportation systems for the post-COVID-19 world in order to reallocate public space, widen sidewalks and make more room for nature.


To reap the benefits of green spaces, parks don’t have to be large. Smaller projects—even a neighborhood garden—can expand outdoor green space.

Urban artists, designers, ecologists and others can play a direct role, too, by creating pop-up parks and green spaces. Some have transformed parking spaces into miniparks with grass, potted trees and seating—for just the time available on a meter. Creating and expanding parks also generates jobs and economic activity, with much of the money spent locally.

Or, cities and the federal government could invest a little more. The United States has historically driven economic recovery with major infrastructure initiatives, such as the New Deal in the 1930s and the American Recovery and Reinvestment Act of 2009. Such investments could easily include nature-filled areas.

Planning for parks that are more than playgrounds

In the past, a big focus of conservation efforts has been on monetary benefits, such as how many dollars of flood damage was avoided by restoring a wetland? But in recent years, we’ve learned that city green spaces are extremely important for our own well-being and central to our mental health. Although parks won’t cure COVID-19, they are far more than playgrounds.


Green spaces are important for our physical and mental health. Although they won’t cure COVID-19, they are far more than mere playgrounds.

And while the essence of happiness has been pondered by philosophers for centuries and studied by psychologists for decades, this new study suggests it might be as simple as this: people feel happier when they’re surrounded by nature.

So, now, I wonder, how much more could we boost our happiness if we spend just a little part of Christmas Day in a park?

Here’s to finding your true places and natural habitats,