Peak Sun Hours in Saltillo, Coahuila, Mexico
- Solar zone
- Zone 4 (excellent)
- Best month
- June (6.8)
- Worst month
- December (3.8)
- Climate
- Temperate · 18.6°C
Monthly solar breakdown
| Month | GHI | Clear-sky | DNI | DHI | Temp °C | Humid % |
|---|---|---|---|---|---|---|
| Jan | 3.97 | 4.90 | 5.47 | 1.27 | 11.6 | 51 |
| Feb | 4.86 | 5.86 | 6.13 | 1.43 | 14.1 | 44 |
| Mar | 5.73 | 6.97 | 6.30 | 1.71 | 16.9 | 41 |
| Apr | 6.39 | 7.77 | 6.21 | 2.05 | 20.8 | 37 |
| May | 6.49 | 8.02 | 5.83 | 2.16 | 23.2 | 45 |
| Jun | 6.76 | 8.20 | 6.27 | 2.14 | 24.0 | 52 |
| Jul | 6.43 | 8.02 | 5.50 | 2.27 | 23.2 | 57 |
| Aug | 6.42 | 7.66 | 6.05 | 2.05 | 23.0 | 58 |
| Sep | 5.21 | 6.85 | 4.72 | 1.99 | 20.7 | 66 |
| Oct | 4.98 | 5.98 | 6.14 | 1.38 | 18.8 | 61 |
| Nov | 4.21 | 5.04 | 6.02 | 1.15 | 14.9 | 57 |
| Dec | 3.79 | 4.58 | 5.63 | 1.14 | 12.2 | 51 |
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 3.79 kWh/m²/day, 0.77 system efficiency.
About solar in Saltillo
Saltillo, Mexico has a temperate climate with meaningful seasonal variation in solar resource. Its annual peak sun hours average 5.44 kWh/m²/day, a excellent solar resource by global standards.
The strongest month in Saltillo is June (summer) at 6.76 kWh/m²/day, and the weakest is December (winter) at 3.79 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.
Saltillo'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 Saltillo?
- Saltillo averages 5.44 peak sun hours per day annually, ranging from 3.79 in December to 6.76 in June.
- How many solar panels do I need in Saltillo?
- Panel count depends on your daily load. At Saltillo's annual average of 5.44 kWh/m²/day, a 5 kWh/day load needs roughly 3 × 400 W panels. Use the calculator above for your actual load.
- What size battery do I need in Saltillo?
- Sizing against Saltillo's worst month (December, 3.79 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 Saltillo's solar resource compare globally?
- Saltillo sits in solar zone 4 out of 5 (where 5 is strongest) at 5.44 kWh/m²/day — excellent 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 Saltillo?
- Saltillo's worst month (December) delivers 3.79 kWh/m²/day — about 56% of the summer peak of 6.76. Off-grid systems here typically oversize 1.5–2× or pair with a backup source.
- Do cloudy days significantly affect Saltillo's solar?
- Partly. Diffuse light still produces 10–25% of clear-sky output. Saltillo's 5.44 kWh/m²/day already reflects average cloudiness, so no further derating is needed for sizing.
- What panel tilt works best in Saltillo?
- At Saltillo's latitude (25°), a fixed tilt near 25° balances year-round yield. Winter-heavy loads favor latitude + 15°; summer-heavy, latitude − 15°.