Best Solar Panel Angle for Every Month
Why Monthly Adjustment Works
The sun's position in the sky changes continuously throughout the year because the Earth is tilted 23.44° on its axis. In summer, the sun arcs high overhead. In winter, it traces a low path across the southern sky (in the northern hemisphere). Monthly tilt adjustment follows this change, keeping your panels perpendicular to the sun's rays as closely as possible. The result? Up to 15% more annual energy compared to a fixed year-round mount, and 25% more compared to a flat roof mount.
The Formula Behind Monthly Tilts
The optimal tilt for any given month follows a clean mathematical pattern derived from the sun's declination: Optimal Tilt = |latitude - 23.45 × cos(2π × (month + 10) / 12)|. In this formula, month 1 = January, month 12 = December. The result is a smooth wave: steepest in December (winter solstice), shallowest in June (summer solstice). The 23.45° multiplier matches the Earth's axial tilt. The +10 shifts the wave so the peak aligns with winter. The absolute value ensures the result stays positive.
Full Monthly Table: New York (40°N)
Here are the exact monthly optimal tilts for New York City: January: 56° | February: 49° | March: 38° | April: 26° | May: 17° | June: 14° | July: 16° | August: 24° | September: 35° | October: 46° | November: 54° | December: 58° The range spans from 14° in June to 58° in December — a dramatic 44° swing. Adjusting every two months (Feb: 49°, Apr: 26°, Jun: 14°, Aug: 24°, Oct: 46°, Dec: 58°) captures most of the benefit with half the effort.
Full Monthly Table: Phoenix (33°N)
For Phoenix, Arizona, the warmer sunbelt climate means slightly shallower angles year-round: January: 49° | February: 42° | March: 31° | April: 20° | May: 11° | June: 8° | July: 10° | August: 17° | September: 28° | October: 39° | November: 47° | December: 51° Notice that June and July tilts are in the single digits — the summer sun is nearly directly overhead in Phoenix. Winter tilts are still substantial at 49–51° to catch the low winter sun.
Full Monthly Table: Port-au-Prince, Haiti (18.5°N)
Tropical locations have much less variation, making monthly adjustment less critical but still beneficial: January: 36° | February: 30° | March: 20° | April: 9° | May: 5° | June: 5° | July: 7° | August: 13° | September: 23° | October: 33° | November: 39° | December: 42° The range is only 5° to 42° — a 37° swing, but the summer angles are extremely shallow (5°), essentially flat. At these latitudes, the sun passes nearly overhead in summer, and even flat-mounted panels capture good energy.
Practical Tips for Monthly Adjustment
If you plan to adjust monthly, here are some tips: Mark your calendar. Set a recurring reminder for the 1st of each month. The 2–3° change between adjacent months is small enough that exact timing doesn't matter. Use an adjustable mount. Ground mounts and some roof mounts allow tilt adjustment. RV and boat owners typically have easy access to their panels. Label your settings. Use a marker to note the angle for each month on your mounting hardware. Then you can adjust by aligning marks rather than measuring each time. Two-month intervals. Adjusting every other month (6 times per year) captures about 95% of the benefit of monthly adjustment with half the work. For most people, this is the sweet spot.
Frequently Asked Questions
Do I really need 12 different angles? No. Monthly adjustment is for maximum yield. Seasonal adjustment (twice per year) captures the vast majority of the benefit. Is monthly adjustment worth it for rooftop panels? If you have easy access to your roof and an adjustable rack, yes. If your panels are flush-mounted on a fixed-pitch roof, monthly adjustment probably isn't practical. Can I automate monthly tilt adjustment? Yes, some solar tracking systems do this automatically. They're called "single-axis trackers" and can boost production 15–25%. Will my panels break from frequent adjustment? Quality adjustable mounts are designed for repeated use. Just don't force anything — if a bolt won't move, use penetrating oil. Use the [tilt calculator to generate a custom monthly schedule for your exact latitude.
Put these numbers to work with SolarAlign
The app uses your phone's sensors to help you align panels to the exact angles discussed in this article. No tools required.Get the app →