Cold-weather warfare
Dry cold – From 19 to −4 °F (−7 to −20 °C). Dry cold conditions are easier to live in than wet cold conditions. Like in wet cold conditions, proper equipment, training and leadership are critical to successful operations. Wind chill is a complicating factor in this type of cold. The dry cold environment is the easiest of the four cold weather categories to survive in because of low humidity and the ground remains frozen. As a result, people and equipment are not subject to the effects of the thawing and freezing cycle, and precipitation is generally in the form of dry snow.
Intense cold – From −5 to −25 °F (−21 to −32 °C). This temperature range can affect the mind as much as the body. Simple tasks take longer and require more effort than in warmer temperatures and the quality of work degrades as attention-to-detail diminishes. Clothing becomes more bulky to compensate for the cold so troops lose dexterity. Commanders consider these factors when planning operations and assigning tasks.
Extreme cold – From −25 to −40 °F (−32 to −40 °C). In extreme cold the challenge of survival becomes paramount as personnel withdraw into themselves. Weapons, vehicles and munitions are likely to fail in this environment.
Hazardous cold – From −40 °F (−40 °C) and below. Units require extensive training before operating in these temperature extremes.
The combined cooling effect of ambient temperature and wind (wind chill) is an important factor that affects troops.

Snow: For military purposes, the U.S. Army categorizes snow as light, moderate, or heavy. Each classification affects visibility and ground movement due to accumulation and is quoted below:

Light snow – Visibility is equal to or greater than 5⁄8 mile (1,000 m) in falling snow. A trace to one inch (2.5 cm) per hour accumulates.
Moderate snow – Visibility is 5⁄16 to 1⁄2 mile (500 to 800 m) in falling snow. One to three inches (2.5 to 7.6 cm) per hour accumulates.
Heavy snow – Visibility is less than 1⁄4 mile (400 m) in falling snow. Three inches (7.6 cm) or more inches per hour accumulates.
Snow and snowdrifts can create advantages on the battlefield by filling in ditches and vehicle tracks and flattening the terrain. It also creates hollows on the downwind side of obstacles, such as trees, buildings, and bushes, which provide observation points or firing positions. Snowdrifts may provide cover for soldiers to approach an objective. Soviet Army doctrine cited 30 centimetres (12 in) as the threshold snow depth that impairs mobility for troops, cavalry and vehicles, except tanks for which the threshold was 50 centimetres (20 in).

Thaw: Thawing conditions can impair mobility and put soldiers at risk of trench foot by turning soil to mud; it can also weaken and break up ice cover on bodies of water. Maintaining roads becomes more difficult during spring-thaw run-off periods and requires mud removal by heavy equipment. Slushy and muddy ground causes clothing and equipment to become wet, damp and dirty. Muddy conditions greatly inhibited Napoleon's ability to maneuver in Russia in the autumn of 1812 and also the German attempt to take Moscow in the autumn of 1941.
The 1942 Taschenbuch für den Winterkrieg acknowledges that neither tracked nor wheeled vehicles can maneuver during conditions of thaw and that aircraft operations must be constrained to concrete runways. It addresses minimizing the use of roads during this period and dismantling bridges that are likely to be taken out by ice floes. It emphasizes how positions in frozen soil must be improved to avoid deterioration from thaw and the necessity of changing uniforms from ones for cold to those for wet conditions.

Tactics: The dominant tactical concern in cold conditions is the ability to maneuver in vehicles or on foot. Additionally, during winter, night operations become the norm at higher latitudes with their long periods of darkness. Snow enhances night vision because of high reflectivity and the visibility of combatants against the white background.

Mounted movement: The German Taschenbuch für den Winterkrieg emphasizes reconnaissance to ascertain the conditions and capacity of the roads to be used. It describes snow clearing from roads and recovery of bogged-down vehicles.
Soviet Army doctrine emphasized the use of sleds for transporting machine guns and mortars over snow, towed in a train by tracked tractors. It addressed the need to pre-heat tanks for use in winter and their application in advance of marching troops to take out enemy positions.
Finnish military doctrine calls for small-unit movements with Anti-tank guided missiles and multiple launch rocket systems to attack foreign forces that have entered the country.
U.S. Army guidance advocates that over snow-covered terrain, vehicles may be employed to establish and maintain trails by establishing a well concealed track with the first vehicle, followed by a vehicle traveling offset from the track of the first, to flatten the trail, and subsequent vehicles widening and flattening the trail. Marked trails avoid obliteration in snowstorms or drifting conditions.  In mountainous terrain, tracked vehicles, including tanks, infantry fighting vehicles, and cavalry fighting vehicles, rarely accompany dismounted infantry in the assault.  Instead, they assist forces by occupying positions where they can use their firepower to isolate enemy objectives.

Dismounted movement: The German Taschenbuch describes preparation and conduct of marches and advocates maintaining slow, steady progress with brief stops to avoid exposure to the wind, and the provision of warm beverages by support vehicles along the way.
Soviet Army doctrine emphasized the use of ski troops for dismounted operations over snow.
U.S. Army guidance explains that troops moving in a wedge-like "column" formation travel more slowly, with no one breaking the trail in undisturbed snow, than the in-line file formation. Therefore, column formation is reserved for imminent enemy contact. As slope angle increases, the amount of travel time is likely to increase substantially.

Water crossings: The German Taschenbuch describes the assessment and reinforcement of ice crossings and also the opportunity to use them as tank traps by removing the ice and bridging the gap with a weak structure, disguised as reinforced ice. It offers the following guidance for crossing ice sheets:

The Soviet Army was an early adopter of a protocol for winter warfare. Its doctrine described the assessment and reinforcement of ice crossings and suggested the use of frozen lakes and rivers as expeditionary airfields, located close to the front to take advantage of short daylight hours in winter.
According to the U.S. Army, rivers found in cold regions may be major obstacles. Subarctic rivers usually have many braided channels and swift currents. During spring and early winter, rivers may become impassable due to freezing or thawing ice flows. Once firmly frozen, rivers may offer routes for both mounted and dismounted movement. Some swampy areas do not freeze solidly during the coldest periods of winter to support troop movements. Nonetheless, it is possible to construct "ice bridges" to thicken an iced-over waterway, using pumps or some other means of flooding the ice-covered area, when temperatures are below −12 °C (10 °F) and the pre-existing natural ice is thicker than 10 centimetres (3.9 in) to support the construction activity.

Snow camouflage: Armies have made use of improvised and official snow camouflage uniforms and equipment since the First World War, such as in the fighting in the Dolomite Mountains between Austria-Hungary and Italy. Snow camouflage was used far more widely in the Second World War by the Wehrmacht, the Finnish Army, the Soviet Army and others. Since then, snow variants of disruptively patterned camouflage for uniforms have been introduced, sometimes with digital patterns. For example, the Bundeswehr has a Schneetarn (snow) variant of its widely used Flecktarn pattern.
Soviet Army doctrine emphasized the importance of camouflage over positions and the need to remove telltale signs of artillery actions, such as smoke stains or shell casings. It also cited the usefulness of decoy targets. It describes the establishment of breastworks made from snow 2 to 3 metres (7 to 10 ft) thick, ice 1.5 metres (5 ft) thick or soil and wood 0.9 metres (3 ft) thick.

Materiel: Snow, ice and cold temperatures affect munitions and military vehicles.
Munitions – Snow, ice, frozen ground, and low temperatures affect mine-laying operations. Burying mines in a frost layer may be difficult, requiring mines to be placed on top of the ground and then camouflaged. Snow or ice may prevent detonation, owing to freezing the firing device or isolating from pressure above. This can be mitigated with plastic laid over the top of the mine.
Vehicles – Adaptations of military vehicles to winter operations include tire chains for maintaining traction of wheeled vehicles. Diesel engines start less well in cold and may require pre-heating or idling during cold periods. A variety of military vehicles have been developed for over-snow travel, including the Sisu Nasu, BvS 10, and M29 Weasel.

Military engineering: Military engineers design and construct transportation and troop-support facilities. In cold climates frozen ground can make digging difficult. Soviet Army doctrine gave them the responsibility to establish build and maintain routes, including water crossings, build and destroy obstacles that require special equipment, construct and maintain airfields, and to build shelter for personnel.