Flying Drones in Winter: Snow, Safety, and What It Means for Photogrammetry Surveys

Winter brings a different set of challenges for construction sites, and for the drones surveying them. Shorter days, colder temperatures and, occasionally, a blanket of snow can all influence how aerial surveys are planned, flown and processed. While winter conditions rarely stop surveys altogether, they do require experience, care and a clear understanding of how environmental factors affect both safety and data quality.

At Drone Surveying, winter flying is very much part of our year-round service. With the right planning and techniques, snow-covered sites can still deliver reliable, accurate data… and in some cases even reveal useful insights that aren’t obvious at other times of year.

How Snow Affects Photogrammetry on Construction Sites

Photogrammetry relies on identifying and matching visual features across thousands of overlapping images. Snow changes how the ground looks, and that has a direct impact on how easily our processing techniques can create an accurate surface model.

Reduced Visual Texture

Fresh snow creates large, uniform white areas with very little contrast. Roads, hardstandings and formation layers can all appear visually similar, making it harder to find common tie points between images. This can, in some cases, reduce model density or accuracy in affected areas.

Masking of Site Features

Snow can temporarily hide edges, kerbs, drainage runs, stockpile toes and formation changes. While major earthworks are usually still apparent, finer detail can be softened or obscured, particularly where snow has drifted or compacted unevenly across the site.

False Elevation Effects

Snow adds physical depth. Even a few centimetres of coverage will be interpreted by photogrammetry as part of the surface, potentially inflating levels slightly. On cut & fill or stockpile volumes, this can introduce small but measurable discrepancies if not accounted for.

Lighting and Reflectivity

Snow is highly reflective. On bright winter days, glare can reduce image quality or wash out detail, particularly at low sun angles. Conversely, on overcast days, snow can create very flat lighting that reduces shadow definition, another cue used to help define surface shape.

When Snow Can Actually Be Helpful

It’s not all downside. In some situations, snow can highlight underlying features:

• Drainage routes and low spots often become visible as snow melts unevenly

• Vehicle routes and trafficking stand out clearly where snow is compressed or cleared

For progress monitoring, sequencing, stockpile measurement and high-level earthworks checks, winter surveys often remain perfectly fit for purpose.

Cold-Weather Flying: Safety Comes First

Winter flying places additional demands on both aircraft and crew. Our operating procedures are adapted seasonally to manage these risks.

Battery Performance

Cold temperatures reduce battery efficiency and available flight time. Batteries are kept warm prior to flight and monitored closely in-air, with conservative return-to-home margins to ensure safe landings.

Propeller Icing

Moist air combined with low temperatures can lead to ice forming on propellers, even when there’s no visible snowfall. This adds weight, reduces lift and can destabilise the aircraft. Flights are paused immediately if icing is suspected, and conditions are continually reassessed throughout operations.

Wind and Weather Variability

Winter weather can change rapidly. Gust fronts, squalls and thermal shifts are more common, particularly on exposed sites. Wind limits are strictly observed, and flights are planned with clear escape routes and contingency landing zones.

Reduced Daylight

Shorter days limit flying windows. Surveys are carefully scheduled to make best use of available light while maintaining safe buffers for unexpected delays.

Ground Conditions

Snow and ice affect take-off and landing zones as well as crew safety. Launch areas are checked and prepared to ensure stable footing and clean sensor optics.

Planning Surveys Around Snowfall

When snow is forecast or already on the ground, survey objectives become especially important. For some deliverables, such as high-precision volume calculations or formation-level verification, waiting for thaw conditions may be advisable. Our pilots are experienced and will make a judgment call on the day of flight based on the specific project requirements – we’d rather postpone a flight until ground conditions have returned to normal than deliver less accurate data. For others deliverables, including progress tracking, visual records or high-level modelling, winter surveys can proceed with confidence.

Where required, we clearly communicate any limitations introduced by snow cover and advise on how data should be interpreted. Transparency and usability remain central to how we deliver every dataset.

Reliable Data, Whatever the Season

Winter doesn’t stop construction, and it doesn’t stop drone surveying either. With experienced pilots, robust procedures and an understanding of how snow and cold affect photogrammetry, surveys can continue safely and effectively throughout the colder months.

If you’re planning surveys over winter and want to understand what’s achievable, and how best to get the data you need, our team is always happy to advise.