Why do gray days make me feel down?
Mostly because of light. A heavily overcast day can be ten or more times dimmer than a sunny one, and your brain uses daylight to set its clock and steady your mood. Weeks of dim days can leave people sluggish and low.
Less sun on your skin.
Less light for the clock that sets your mood and sleep.
Show me why1 min
How much light you're really getting
Light is measured in lux. Bright sun can top 100,000 lux. A heavily overcast day may be closer to 1,000 to 10,000. A lit living room is a few hundred. Your eyes adjust so well that you barely notice the difference, but the light-sensing cells that set your body clock do.
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Light sets your clock
Morning light tells your internal clock it's daytime, which shapes when you feel alert and when you get sleepy. On short, dim winter days that signal is weaker. Researchers think the change affects brain chemicals that help regulate mood, such as serotonin, along with melatonin, the hormone that makes you sleepy.
Winter blues, or something more
A mild, passing low mood on dark days is common. When low mood comes back in the same season year after year and gets in the way of life, it may be seasonal affective disorder (SAD), a type of depression. It's treatable: one standard option is sitting near a 10,000-lux light box for about half an hour most mornings, under a provider's guidance. If your mood shifts with the seasons, talk to a health care provider. If you're struggling, in the US you can call or text 988.
Questions people ask
- Does weather really affect mood?
- For many people it does, mostly through daylight. Effects vary a lot between people, and long stretches of dim days matter more than one cloudy afternoon.
- How bright is a cloudy day?
- Often a few thousand lux, still many times brighter than indoor lighting. Getting outside on a gray morning gives your body clock more light than staying in.
- What is seasonal affective disorder?
- A type of depression that returns in the same season, most often fall and winter. It's treatable with light therapy, talk therapy and other options; a health care provider can help.