So far, this winter has been unseasonably mild in much of Ukraine. As CNN drove from the eastern port city of Mariupol to Zaporizhzia in central Ukraine on February 1, it began to rain. The driver shrugged in disbelief. “Should be snow,” he laughed.
In Zaporizhzia, crusted banks of snow were melting into a trickle of brown water. Even at midnight, as a shroud of mist lay over the River Dnieper, the temperature hovered at freezing. Sleet turned to drizzle and back again.
Military analysts are debating whether a continuation of the mild winter might affect any plans for an offensive. The Kremlin has repeatedly denied it has any intent to attack Ukraine, but more than 100,000 Russian troops are gathered close to the borders of Ukraine, along with heavy weapons, tanks and ballistic missiles.
Social media videos from several areas where Russian forces are deployed — some posted by soldiers themselves — show soft and flooded ground, and plenty of mud.
Data from Copernicus, the EU’s Earth Observation program, shows that much of eastern Europe experienced well-above-average temperatures in January. Ukraine saw temperatures between 1 to 3 degrees Celsius higher than the average of the past 30 years, one of many changes that the climate crisis has brought this region.
Copernicus also notes that in January, “eastern Europe was predominantly wetter than average” and the soil in Ukraine was wetter than normal. The combination means less frost and more mud.
That’s no surprise to Svitlana Krakovska, head of the Applied Climatology Laboratory at the Ukrainian Hydrometeorological Institute in Kyiv.
“What we’re seeing on a long-term trajectory is a lower number of days with snow cover as well as frost nights. We definitely see much stronger warming happening here than the global average,” she told CNN.
The US assessment is that a Russian incursion would be easier if the temperature falls.
“[Russian President Vladimir Putin] is going to have to wait a little bit until the ground is frozen so he can cross,” US President Joe Biden said at a news conference last month.
At a Pentagon briefing at the end of January, the Chairman of the Joint Chiefs of Staff, Gen. Mark Milley, said that when Ukraine’s “high water table” freezes, “it makes it for optimal conditions for cross-country tract and wheeled vehicle maneuver.”
US officials have said Putin would understand that he needs to move by the end of March.
But Dara Massicot, a senior policy researcher at the RAND Corporation, says that “while frozen ground would be a ‘nice to have’ for Russian forces, it’s not a determining factor. It’s important to keep in mind that precision-guided missiles and airstrikes are not influenced by this factor.”
Russian forces have substantially improved over the last decade, says Massicot. The air force has acquired better targeting and communications — and many of its pilots have gained combat experience in Syria.
“The Russian military trains year-round so they have experience with different weather conditions.”
Russian tanks — hundreds of which now sit within reach of Ukraine’s border — are not much impeded by soft ground, though they’d likely make quicker progress over frozen ground.
Even so, armor moves only as fast as its logistical tail, vehicles that could be slowed by bad weather “if they had to go off-road for some reason,” says Massicot. She notes that Russia has forward-deployed logistical equipment to help overcome such problems, including recovery vehicles and bridging materials.
Pontoon bridges have also been observed on rail convoys traveling into Belarus since late January.
Ground conditions would matter more in some places than others. Eastern Ukraine is rolling farmland, ideal tank country. But the northern border with Belarus includes thousands of square miles of bog and marsh that would impede an attacking force (as it did the Nazis in 1941 during Operation Barbarossa.)
According to the Institute for the Study of War, “The marshes can be difficult, in some places likely impossible, for mechanized forces to traverse when wet.”
Much depends on the sort and scale of military operation that Russia might have in mind. In the early stages of a conflict, air and missile attacks would be more important than a surge of mechanized units.
“The skies would not be a factor for Russian precision guided cruise or ballistic missiles, or even some of their more accurate long-range artillery systems,” says Massicot, who was formerly a senior analyst at the Pentagon on the Russian military. “Cloud cover is especially not a factor for fixed locations like military facilities or command and control where coordinates are known.”
Russia has moved a substantial number of Iskander ballistic missiles, which have a range of about 300 miles (450 kms) close to Ukraine in the last month.
In the east, Ukrainian frontline positions have not moved for years; missiles and long-range artillery could target them regardless of weather — perhaps providing a breakthrough point for Russian armor.
Attack aircraft, which would be tasked with attacking Ukrainian units on the move, would need relatively clear skies. So would planes for dropping air assault troops into the conflict zone; according to defense analysts Janes, “multiple airborne forces (VDV) units have also been identified deploying into Belarus.”
A low cloud-base hinders air operations as well as satellite reconnaissance, and might blunt Russia’s considerable air superiority, making for what one military analyst called “a fairer fight.”
But it’s a double-edge sword. Dense cloud (and night) cover would allow the Russians to move troops forward to start-lines without being detected from above. Should the Kremlin decide to attack, a period of bad weather followed by clear skies once operations are underway would be optimal.
The skies would matter to the Ukrainians too. If they opted for a highly maneuverable defense, they would require airborne intelligence provided by the US and NATO to focus limited resources on key points to blunt the Russian advance.
Of course, weather conditions are not the only — nor the major – consideration for the Kremlin. The progress (or lack thereof) of negotiations on Russia’s published demands sent to the US and NATO will likely be the decisive factor. Devising some justification — a casus belli — for going to war would provide important messaging for a skeptical Russian public. Shaping the information war is a key part of Russian strategy.
A changing climate
Krakovska, an author of the Intergovernmental Panel on Climate Change report published last year, says there is a clear connection between climate change and Ukraine’s changing winters.
That’s particularly pronounced in Eastern Ukraine, where winter temperatures are around 3 degrees Celsius warmer on average than they were in the 1960s.
“Thirty years ago, we would have had snow cover, especially in [eastern Ukraine], for at least three months of the cold season, and we’d have frost nights for around five months,” Kralovska said.
“In 2020, we didn’t really have a winter at all, just a few days were under zero, and we didn’t have much snow, just a little.”
Russian President Vladimir Putin used to be ambivalent about global warming. Back in 2003, he even said that “Maybe climate change is not so bad in such a cold country as ours? 2-3 degrees wouldn’t hurt.”
More recently he has acknowledged the damage it is doing to Russia’s environment.
Now it might affect his generals’ calculations.
The winter weather in Ukraine can be fickle, but the outlook for the rest of February in Kyiv is milder than the average, local meteorologists say, with most daytime temperatures well above freezing and the very occasional splash of sunshine.
Timko, Ukraine’s very own groundhog, apparently thinks the Rasputitsa mud may be a little earlier this year. He didn’t see his shadow when he emerged from hibernation last week.
CNN’s Angela Dewan, Brandon Miller and Gianluca Mezzofiore contributed to this report.