Seattle residents suffer from acute rain denial. When it rains, they walk around and get wet. Oh yes, they carry umbrellas — they just refuse to open them. That would mean acknowledging that it rains in Seattle, and as any Seattlite can tell you — and will, repeatedly — it rains more in New York than it does in Seattle.

Technically, this might be true. But as someone who lived in Seattle for two years and then moved to New York, I know for a fact that New York has something Seattle doesn’t: sun.

And sun is everything.

Weather-sensitive people can be like human barometers, capable of predicting the weather by the aches in their bones or the black clouds hanging over their heads.

I grew up in Indiana, which has some of the world’s worst weather: 100 degrees and 100 percent humidity in the summer, tons of tornadoes in the spring, blizzards and sub-zero temperatures all winter long. Indianapolis residents suffer from acute snow denial: During my 25 years there, every snowfall came as a big surprise that paralyzed the city.

Despite that, I never realized how weather sensitive I was until I moved to Seattle, which is as gray as it is green.

In the Emerald City, it snizzles, which is drizzle that feels like someone sneezing in your face. In the winter, the sun comes up around 10 a.m. — you know because it goes from dark gray to medium gray outside — and it’s dark again by 3:30 p.m. By February, I was ready to gnaw my arm off. Instead, I went to Mexico for two weeks.

And it’s not just the winter: One year the sun didn’t shine for the entire month of June.

Do I have seasonal affective disorder, appropriately known as SAD? Oh yeah. Overeating, oversleeping, cravings for mass quantities of chocolate and an intense desire to curl up in a fetal position under the bed and never come out — that was me. Me and 15 million other people.

Gray days can make for a gloomy mindset in weather-sensitive people. Drops in barometric pressure and reductions in daylight can trigger aches, pains and the blues.

A year before I experienced my own raging SAD, psychiatrist Norman Rosenthal was busy defining it. Rosenthal was the first to recognize SAD as a syndrome and treat it with light therapy.

People with SAD get sad when they’re deprived of daylight, so it kicks in as the days get shorter, peaking in January and February. It’s estimated that 6 percent of the population suffers from winter depression, and as many as 20 percent might have a milder form. Though it’s more common the farther north you go, people can suffer from SAD in even bright climes.

SAD is associated with decreased serotonin — one of those crucial feel-good brain chemicals. It’s also associated with increased production of melatonin, which makes you want to snooze.

A less common type of SAD, known as summer depression, usually begins in the late spring or early summer. Doctors speculate that the culprit is too much heat, which some people find intolerable, and too much daylight, which kicks up adrenaline production and reduces melatonin, resulting in irritability and difficulty sleeping.