North Country · Tug Hill Plateau
Lewis County weather and solar
What the climate here actually does to a solar array — production by season, the structural spec the snow load forces, and the roof decisions that follow from both.
The climate
Tug Hill Plateau
Specific yield
980–1,120 kWh / kW-DC / yr
A 10 kW array averages about 10,500 kWh a year here.
Modeled NREL PVWatts v8 · verified Jan 2026
Mean annual snowfall
150–250 inches
Extreme lake-effect exposure from Lake Ontario, upslope-enhanced.
Modeled NOAA/NWS seasonal snowfall records · verified Jan 2026Some Tug Hill stations have recorded over 300 inches in a single season.
Design ground snow load
90–150 psf
Racking and structural review are engineered to this figure. Ask which number your proposal used.
Filed ASCE 7 ground snow load data · verified Jan 2026Large parts of this zone are designated case-study areas where a site-specific engineering determination is required rather than a mapped value.
Winter quarter share
8% of annual
December, January, and February combined.
Derived NREL PVWatts v8 · verified Jan 2026
Days with snow on the array
50–95 per season
Far fewer than days with snow on the ground — panels shed.
Observed GridReady quote and bill review sample · verified Jan 2026
Seasonality
Production month by month on a 10 kW array
kWh per month from a 10 kW-DC array at the midpoint of the Tug Hill Plateau yield band. Bar height is relative to the peak month.
Show the arithmetic
10 kW × 1,050 kWh/kW/yr (midpoint of the Tug Hill Plateau band) = 10,500 kWh a year, distributed on a northern-temperate seasonal curve anchored so December through February sums to 8% of the total.
A modeled shape, not a measurement of your roof. Orientation, pitch, and shading move individual months more than they move the annual total.
Derived NREL PVWatts v8 · verified Jan 2026
Local weather
What the weather here specifically does
- Winter production here should be modeled as close to zero for stretches, not merely reduced. A proposal that shows smooth monthly production through January in Tug Hill country is not modeling this place.
- Structural review is not a formality. Some roofs genuinely cannot carry an array plus this snow load.
- Outage duration is the longest in the state. If you are here and considering backup power, the case is about days, not hours.
The roof
Consequences for the array itself
- Expect a site-specific structural determination rather than a mapped snow-load number.
- Ground mounts need unusual height above grade. Standard racking heights get buried.
- Steep pitch is a real advantage here and worth weighting in array-plane selection.
The one question worth asking every installer here
“What ground snow load is this racking engineered for, and can I see the stamped calculation?” The right answer in Lewis County is 90–150 psf. At this load, structural review is genuine engineering and some roofs will need reinforcement. That is a finding, not a sales objection.
Microclimates
Lewis County is not one climate
| Zone | Snowfall | Snow load | Specific yield |
|---|---|---|---|
| Tug Hill Plateau (primary) | 150–250" | 90–150 psf | 980–1,120 kWh/kW |
| Adirondack Interior | 90–180" | 70–130 psf | 1,020–1,160 kWh/kW |
By location
Elevation across Lewis County
| Place | Elevation | Climate zone | Guide |
|---|---|---|---|
| Lowville | 860 ft | Tug Hill Plateau | Costs & production |
Questions
Lewis County climate FAQ
- How much does snow reduce solar production in Lewis County?
- Less than most people expect. A pitched array here sees roughly 50 to 95 days a season with enough cover to stop production — the glass is slick and the array runs warmer than the shingles around it. Cloud cover through November and December costs more production than snow cover does. What snow really drives is the structural spec: design ground snow load here is 90 to 150 psf, and racking must be engineered and stamped for it.
- What is the seasonal production curve in Lewis County?
- Jul is the strongest month and Dec the weakest, by roughly 5.6 to one. December through February combined account for about 8% of annual output — roughly one month's worth of production spread across three months. A proposal that shows a smooth, near-flat monthly production curve for this county is not modeling this climate.
- Is Lewis County too far north or too cloudy for solar?
- No, but the honest framing is that the climate sets the ceiling and the electricity rate sets the value. A 10 kW array here produces roughly 10,500 kWh a year. That is real output — the question is what a kWh is worth where you live, which is a rate question rather than a weather one.
- How does lake-effect snow affect solar in Lewis County?
- Extreme exposure from Lake Ontario, upslope-enhanced. Winter production here should be modeled as close to zero for stretches, not merely reduced. A proposal that shows smooth monthly production through January in Tug Hill country is not modeling this place.
- Does cold weather help or hurt solar panels in Lewis County?
- Cold helps efficiency — panels produce more per unit of sunlight at low temperature, which is why a clear February day can outperform a hazy July one on a per-hour basis. What hurts is daylight hours and cloud cover, and this climate is short on both between November and February. The two effects do not cancel out; the daylight loss dominates.
Next step
Turn this into your own numbers
The climate sets what a roof can produce. Your rate sets what that production is worth, and your roof sets how much of the band you actually get.
How this page is built
This is a generated page: the structure is shared across locations, the numbers are not. Every figure comes from the source cited beside it, with the date we last checked it. Nothing here is a quote, an appraisal, or tax advice, and none of it is specific to your roof.
Rates and incentive programs change. We re-verify utility tariffs and NYSERDA program status on a rolling schedule and stamp the date on each number rather than on the page, so you can see which specific figures are fresh. Full methodology · Program status tracker · About the Local Energy Playbook
Page content last reviewed April 2026.