Palmer was born in Albany, New York, the son of the prominent Neo-Classical sculptor Erastus Dow Palmer, who exposed Walter Launt to the world of art at an early age. Artists as well known as John F. Kensett and Jervis McEntee frequented the Palmer household, and none other than Frederic Edwin Church began tutoring young Palmer in 1870. Church recognized Palmer's prodigious talent, commenting that "I would like to be of use to him before he gets so far advanced as not to require my aid." Palmer and Church maintained a strong friendship throughout the years, and Palmer often visited Olana, Church's vast estate on the Hudson River, where he painted winter scenes. Palmer's work was first accepted for the National Academy of Design show of 1872, when he was only eighteen.

After a European tour in 1873, Palmer continued his art studies in Paris until 1876. One of his masters was Emile Auguste Carolus-Duran, whose influence is seen in the controlled tonality that modifies the academic tightness of Palmer's early work. Subtlety of color, texture, and light became characteristic of all of Palmer's work.

The landscapes of Walter Launt Palmer, particularly his snow scenes, were popular prizewinners throughout a long professional career that began before the artist was twenty years old. Both Church and Palmer celebrated the spiritual side of nature with an emphasis on light and atmosphere. By combining such influences as academic precision, oriental delicacy, and the impressionist effect, Palmer's snowscapes demonstrate his amazing ability to infuse the landscape with magical light and color, especially as the setting sun casts its warm rays upon this landscape titled Cedars at Sundown. It is believed that Palmer was the first artist to use the color blue in depicting the reflection of light on the snow-filled landscape. Maybelle Mann notes in Walter Launt Palmer, Poetic Reality:

Some found his blue shadows hard to understand in an era when this was almost revolutionary. Blue shadows were only a smal part of Palmer's discoveries in painting snow. Delicate pinks, greens, purples and other shades abound on the snow as reflections of light (p. 46).

A 1901 Town and Country article summed up the appeal of Palmer's winter scenes, while emphasizing the complexity involved in creating these seemingly straightforward depictions of nature.

We have had a blizzard of these "snows" and yet not too many. If you will consider for a moment the variety of composition, the luminous quality of his sunlight, that subtle combination of sun and snow; the blue or violet shadow, which years ago caused the critics much agony and which is banal under a superficial workman but masterful in his hands; you cannot fail to recognize a pronounced individuality with a delicate and true quality of color. [Theodore Purdy, "Walter Palmer's Landscapes," September 28, 1901, as quoted in Mann, p. 82]

The artist painted his outdoor scenes in the studio, prefacing each with painstaking preliminary notes and sketches which he put aside when he began to paint.

Palmer was awarded the Hallgarten prize in 1887, given for outstanding work by artists under thirty-five years of age, by the National Academy of Design for his painting January. In that same year, he was elected an Associate of the Academy. Palmer's best-known work and his own favorite Silent Dawn (1920, Metropolitan Museum of Art, New York), is a picture of snow-laden trees above a still brook. After winning more praise for his snow scenes, he was elected to Academician by the National Academy in 1897; his long-time friend William Merritt Chase painted the required portrait following Palmer's election.

Palmer exhibited extensively throughout his lifetime at such prestigious venues as the Brooklyn Art Association, Pennsylvania Academy of the Fine Arts, Boston Art Club, the Paris Exposition of 1900, the Corcoran Gallery of Art Biennials from 1907 to 1912, and the National Academy of Design. His work sold well throughout his lifetime, as he was well represented in many notable New York galleries and was patronized by the likes of Mrs. Theodore Roosevelt. Besides the Hallgarten prize, Palmer received many prestigious awards throughout his career including the gold medal from the Philadelphia Art Club in 1894, gold medal from the Boston Art Club in 1895, Butler award from the Art Institute of Chicago in 1919, and the Dupont award from the Wilmington Art Society in both 1926 and 1928.

Palmer's work can be found in private collections and institutions across the nation such as the National Museum of American Art, Washington, DC; The Metropolitan Museum of Art, New York, NY; Museum of Fine Arts, Boston, MA; Albany Institute of History, Albany, NY; Society of American Artists, New York, NY; Buffalo Fine Arts Academy, Buffalo, NY; Everson Museum of Art, Syracuse, NY; and the Butler Institute of American Art, Youngstown, OH.