Daylight Hours Calculator
Calculate total daylight hours for any latitude and date with monthly breakdown.
Quick Answer
Daylight hours depend on your latitude and the date. At the equator (0°), you get ~12 hours year-round. At 40°N (New York), daylight ranges from 9h 15m (December) to 15h 6m (June). At 60°N (Helsinki), it ranges from 5h 50m to 18h 50m.
Enter your latitude below to see an exact month-by-month breakdown of daylight hours.
Seasonal Daylight Hours by Latitude (Reference Table)
| Latitude | Example City | Mar 21 | Jun 21 (longest) | Sep 23 | Dec 21 (shortest) |
|---|---|---|---|---|---|
| 0° (Equator) | Quito | 12h 7m | 12h 7m | 12h 7m | 12h 7m |
| 25°N | Miami | 12h 7m | 13h 45m | 12h 7m | 10h 32m |
| 40°N | New York | 12h 9m | 15h 6m | 12h 9m | 9h 15m |
| 51°N | London | 12h 10m | 16h 38m | 12h 10m | 7h 50m |
| 60°N | Helsinki | 12h 16m | 18h 50m | 12h 16m | 5h 50m |
| 66.5°N | Arctic Circle | 12h 20m | 24h 0m | 12h 20m | 0h 0m |
Equinox days (Mar 21, Sep 23) are close to 12h everywhere. Day length includes civil twilight refraction adjustment.
How It Works
Enter latitude to see daylight hours for today, plus a month-by-month breakdown showing how daylight changes through the year at your location.
Formula
Frequently Asked Questions
Which city has the most daylight hours?
Cities near the Arctic Circle like Reykjavik, Iceland or Tromso, Norway can have nearly 24 hours of daylight in summer. Near the equator, daylight is close to 12 hours year-round. The annual total is roughly the same everywhere (~4,380 hours), but the distribution across seasons varies dramatically by latitude.
How do daylight hours change with latitude?
At the equator, days are nearly 12 hours year-round. The variation increases with latitude -- at 40°N the range is about 9-15 hours, at 60°N it is roughly 6-19 hours seasonally. Beyond the Arctic Circle (66.5°N), there are periods of 24-hour daylight (midnight sun) and 24-hour darkness (polar night).
Why are daylight hours not exactly 12 hours at the equinox?
Even at the equinox, daylight slightly exceeds 12 hours everywhere because sunrise is defined as when the sun's upper edge appears above the horizon (not its center), and atmospheric refraction bends the sun's image upward by about 0.57 degrees, making the sun visible when it is still geometrically below the horizon.