On Tuesday the supermodel shared a photo of a double rainbow over Manhattan with a message of love.
The couple were married for nearly 24 years at the time of his death and had a daughter together.
"Jan 10th, 2016 NYC Skyline #ForeverAndEver #ForeverLove #BowieForever," she wrote.
Bowie was 69 when he died last year of cancer, which he battled for more than a year. Iman, 61, said on "Good Morning America" in September that she was "holding up" in the months after his death. She also said she planned to wear a "David" necklace every day in his honor.
"I’m wearing this until my death," she said.