Peak Sun Hours in Baltimore, Maryland, United States
- Solar zone
- Zone 3 (good)
- Best month
- June (6.2)
- Worst month
- December (1.8)
- Climate
- Temperate · 12.0°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 2.01 | 3.00 | 3.04 | 0.94 | -1.2 | 84 |
| Feb | 2.86 | 4.13 | 3.62 | 1.26 | -0.0 | 82 |
| Mar | 3.81 | 5.56 | 3.99 | 1.62 | 4.7 | 80 |
| Apr | 4.96 | 6.90 | 4.58 | 2.01 | 11.2 | 77 |
| May | 5.51 | 7.68 | 4.38 | 2.39 | 16.8 | 79 |
| Jun | 6.20 | 7.92 | 4.93 | 2.59 | 22.0 | 76 |
| Jul | 6.17 | 7.57 | 4.92 | 2.52 | 25.0 | 70 |
| Aug | 5.38 | 6.76 | 4.44 | 2.27 | 24.2 | 70 |
| Sep | 4.35 | 5.72 | 4.45 | 1.71 | 20.3 | 72 |
| Oct | 3.17 | 4.39 | 4.04 | 1.22 | 13.2 | 77 |
| Nov | 2.32 | 3.18 | 3.62 | 0.94 | 6.7 | 80 |
| Dec | 1.75 | 2.61 | 2.84 | 0.81 | 1.5 | 85 |
GHI, Clear-sky, DNI, DHI in kWh/m²/day. Data: NASA POWER climatology (long-term monthly averages).
Off-grid calculator
Add appliances
- Add an appliance to size a system.
Sizing
- Daily load
- 0.00 kWh
- Panel wattage
- 0 W
- Panel count (400W modules)
- 0
- Battery bank
- 0.0 kWh
Sizing against worst-month PSH of 1.75 kWh/m²/day, 0.77 system efficiency.
About solar in Baltimore
Baltimore, United States has a temperate climate with meaningful seasonal variation in solar resource. Its annual peak sun hours average 4.04 kWh/m²/day, a good solar resource by global standards.
The strongest month in Baltimore is June (summer) at 6.2 kWh/m²/day, and the weakest is December (winter) at 1.75 kWh/m²/day. When sizing a year-round off-grid system, it's standard practice to design against the December value rather than the annual average — otherwise the battery bank runs low during the darkest weeks.
Baltimore's solar conditions are well within the range where off-grid PV is a straightforward engineering exercise with standard-sized arrays and lithium batteries.
FAQ
- What are the peak sun hours in Baltimore?
- Baltimore averages 4.04 peak sun hours per day annually, ranging from 1.75 in December to 6.2 in June.
- How many solar panels do I need in Baltimore?
- Panel count depends on your daily load. At Baltimore's annual average of 4.04 kWh/m²/day, a 5 kWh/day load needs roughly 5 × 400 W panels. Use the calculator above for your actual load.
- What size battery do I need in Baltimore?
- Sizing against Baltimore's worst month (December, 1.75 kWh/m²/day) with 2 days of autonomy at 80% depth of discharge, a 5 kWh/day load needs about a 12.5 kWh battery bank.
- How does Baltimore's solar resource compare globally?
- Baltimore sits in solar zone 3 out of 5 (where 5 is strongest) at 4.04 kWh/m²/day — good by global standards. For reference, top-tier desert sites average ~6.5 and high-latitude cities around 2.5 kWh/m²/day.
- How much does winter reduce solar output in Baltimore?
- Baltimore's worst month (December) delivers 1.75 kWh/m²/day — about 28% of the summer peak of 6.2. Off-grid systems here typically oversize 1.5–2× or pair with a backup source.
- Do cloudy days significantly affect Baltimore's solar?
- Partly. Diffuse light still produces 10–25% of clear-sky output. Baltimore's 4.04 kWh/m²/day already reflects average cloudiness, so no further derating is needed for sizing.
- What panel tilt works best in Baltimore?
- At Baltimore's latitude (39°), a fixed tilt near 39° balances year-round yield. Winter-heavy loads favor latitude + 15°; summer-heavy, latitude − 15°.