The poem seems to be about loneliness and regret. The white nightgowns that "haunt" the houses refer to brides who do not inhabit these dwellings; the descriptive colors of the absent nightgowns convey a melancholy regret at the loss of energy and joy that might have come with marriage and partnership. The many color combinations echo the change of the seasons, the change in fashions a man living with a woman might recognize. It is an old fashioned set of images conveying an old fashioned sensibility of marriage. "Disillusionment at 10 o'clock" refers quite literally to the feeling of regret and loss that occurs each night at bedtime, when the old sailor, drunk and asleep in his boots (with no helpmeet to assist him in dressing for bed), realizes he is alone. The "red weather" is a sexual image, referring to the constant presence of sexual frustration and possibly anger at being alone. Catching "tigers" is also a sexual image, a fantasy of wild animals and distant shores filling in for the loss of a fulfilling family life the old sailor rejected.
The disillusionment of the title may refer to the absence of illusions (dreams, imagination) or to the poet’s revelation that the people in white nightgowns who go to sleep at 10 o'clock are symbolic of those who lack any imaginative life. The poem contrasts the colorless lives and imaginations of the townspeople of an unidentified town (the white nightgowns) with the vivid and exotic life and imagination of the drunken sailor. In reading the poem, you might begin by thinking of this contrast and determine what you can do in your life to not fall into a pattern of tradition, sameness, and not utilizing as much of the day as possible. One might think to live one's life with vitality and contrast.