Peak Sun Hours in Oklahoma City, Oklahoma, United States
- Solar zone
- Zone 3 (good)
- Best month
- June (6.9)
- Worst month
- December (2.4)
- Climate
- Temperate · 15.9°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 2.82 | 3.63 | 4.69 | 0.95 | 2.8 | 70 |
| Feb | 3.43 | 4.70 | 4.61 | 1.22 | 4.7 | 70 |
| Mar | 4.48 | 6.06 | 4.93 | 1.64 | 10.8 | 67 |
| Apr | 5.53 | 7.28 | 5.42 | 1.96 | 16.0 | 66 |
| May | 5.96 | 7.90 | 5.14 | 2.29 | 21.0 | 69 |
| Jun | 6.92 | 8.15 | 6.28 | 2.32 | 26.0 | 67 |
| Jul | 6.90 | 7.89 | 6.41 | 2.23 | 28.8 | 60 |
| Aug | 6.22 | 7.17 | 6.04 | 2.00 | 28.0 | 61 |
| Sep | 5.14 | 6.14 | 5.67 | 1.63 | 23.4 | 64 |
| Oct | 3.97 | 4.94 | 5.44 | 1.17 | 16.2 | 65 |
| Nov | 3.00 | 3.78 | 4.86 | 0.94 | 9.7 | 68 |
| Dec | 2.40 | 3.25 | 4.06 | 0.87 | 3.8 | 71 |
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 2.40 kWh/m²/day, 0.77 system efficiency.
About solar in Oklahoma City
Oklahoma City, United States has a temperate climate with meaningful seasonal variation in solar resource. Its annual peak sun hours average 4.73 kWh/m²/day, a good solar resource by global standards.
The strongest month in Oklahoma City is June (summer) at 6.92 kWh/m²/day, and the weakest is December (winter) at 2.4 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.
Oklahoma City'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 Oklahoma City?
- Oklahoma City averages 4.73 peak sun hours per day annually, ranging from 2.4 in December to 6.92 in June.
- How many solar panels do I need in Oklahoma City?
- Panel count depends on your daily load. At Oklahoma City's annual average of 4.73 kWh/m²/day, a 5 kWh/day load needs roughly 4 × 400 W panels. Use the calculator above for your actual load.
- What size battery do I need in Oklahoma City?
- Sizing against Oklahoma City's worst month (December, 2.4 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 Oklahoma City's solar resource compare globally?
- Oklahoma City sits in solar zone 3 out of 5 (where 5 is strongest) at 4.73 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 Oklahoma City?
- Oklahoma City's worst month (December) delivers 2.4 kWh/m²/day — about 35% of the summer peak of 6.92. Off-grid systems here typically oversize 1.5–2× or pair with a backup source.
- Do cloudy days significantly affect Oklahoma City's solar?
- Partly. Diffuse light still produces 10–25% of clear-sky output. Oklahoma City's 4.73 kWh/m²/day already reflects average cloudiness, so no further derating is needed for sizing.
- What panel tilt works best in Oklahoma City?
- At Oklahoma City's latitude (35°), a fixed tilt near 35° balances year-round yield. Winter-heavy loads favor latitude + 15°; summer-heavy, latitude − 15°.