Across the year, daylight in St. Louis ranges from about 9h 18m in December to 14h 42m in June — a 5h 24m swing that shapes sleep, mood and training rhythms. From roughly December through February, the sun sits too low for much vitamin D production.
The nearest other Live10X city guide is Indianapolis, about 230 miles away.
St. Louis by the numbers
- County
- City of St. Louis
- Climate
- Humid continental
- Elevation
- under 500 ft
- Latitude
- 38.6°N
- Shortest day
- 9h 18m
- Longest day
- 14h 42m
- Vitamin D winter
- December through February
At a glance
St. Louis at a glance
- Top local priority in St. Louis: a winter movement plan.
- Daylight swings from about 9h 18m to 14h 42m across the year — anchor your wake time and get morning light.
- Sunlight is too weak for much vitamin D production from roughly December through February; a blood test shows where you stand.
- Use Forest Park and the Gateway Arch National Park grounds for easy, regular outdoor movement.
Climate & lifestyle
What living in St. Louis means for your health
St. Louis has a humid continental climate — four distinct seasons, with warm to hot summers and cold winters that bring snow and short days. Seasonal shifts in light and temperature affect sleep, mood, activity and vitamin D, so a winter plan matters as much as a summer one.
- a winter movement plan
- morning light and vitamin D awareness
- consistent sleep through seasonal shifts
- heat-smart training on humid summer days
Light, sleep & vitamin D
Daylight in St. Louis across the year
9h 18m
Shortest day (December)
14h 42m
Longest day (June)
~3 mo
Low-UVB “vitamin D winter”
At about 38.6°N, St. Louis sees a 5h 24m swing in day length between the solstices. Research suggests winter UVB is too weak for meaningful vitamin D production for roughly three months a year. That's roughly December through February. Bright morning light helps anchor your body clock, and a simple blood test shows whether your vitamin D is where it should be.
Calculated from latitude using standard solar formulas and published latitude research. How we calculate this
Local wellness trends
Wellness trends in St. Louis
Winter wellness
Long winters in St. Louis have made indoor training, saunas and morning-light routines part of the local playbook.
Medical & research hub
St. Louis's major health systems mean strong access to preventive care, specialists and clinical research studies.
Rec leagues & sport
From pro teams to adult rec leagues and pickleball ladders, sport keeps St. Louis social and active.
Riverfront greenways
Greenways and riverfront trails give St. Louis car-free corridors for walking, running and cycling.
Local health optimization resources
Places to move, recover and eat well in St. Louis
- ParkForest ParkGreen space for walks, bodyweight workouts and time in nature.
- Parkthe Gateway Arch National Park groundsGreen space for walks, bodyweight workouts and time in nature.
- Trailthe Great Rivers Greenway trailsCar-free miles for zone 2 walks, runs and rides.
Testing
At-home wellness genetic testing
Available throughout St. Louis: order online, collect a sample at home and review results with a qualified professional.
Learn more about at-home wellness genetic testingHealthcare
Preventive care & baseline labs
Primary care clinicians in City of St. Louis can order baseline labs — such as a lipid panel, HbA1c, vitamin D and B12 — useful context for any wellness plan.
Learn more about preventive care & baseline labsNutrition
Farmers markets & local food
St. Louis's food scene makes it easier to eat 30+ different plants a week — shop seasonal produce at local farmers markets.
Learn more about farmers markets & local foodSeasonal playbook
A seasonal wellness playbook for St. Louis
- Winter: short days call for morning light, indoor strength and cardio plans, and a consistent wake time.
- Spring and fall: prime seasons for outdoor running, cycling and hiking.
- Summer: humid heat waves happen — hydrate well and train early on the hottest days.
- Winter light: with only about 9h 18m of daylight in December, get outside in the morning and keep indoor lighting bright during the day.
Recommended reading
The most relevant guides for St. Louis residents
FAQ
St. Louis wellness FAQs
Can I take a wellness genetic test in St. Louis?
How do you stay active through St. Louis's winters?
Can you get enough vitamin D from the sun in St. Louis?
How do seasonal daylight changes in St. Louis affect sleep?
What are good places to exercise outside in St. Louis?
How can St. Louis residents make the most of local healthcare for prevention?
The bottom line
Living well in St. Louis means working with its warm summers and cold, snowy winters: a winter movement plan, morning light and vitamin D awareness and consistent sleep through seasonal shifts. Add the fundamentals — consistent sleep, daily movement, strength training and a whole-food diet — and personalize with the wellness assessment and at-home testing.
