If you’ve ever been on a chairlift when warmer temperatures call for rain but instead noticed snowflakes soaking into your coat, this question applies to you: Can it snow when temperatures are above freezing?
Snow temperatures are cold at cloud level in most cases, causing the precipitation to start out as snow. The snowflakes retain their flakiness and fall as snow if the air temperature is colder than freezing all the way from the cloud to the ground.
Snow forms when the atmospheric temperature is at or below freezing (0 degrees Celsius or 32 degrees Fahrenheit) and there is a minimum amount of moisture in the air. That’s when the snow will reach the ground.
Cold vs. warm air
The air between the cloud and the ground in certain situations is not always below freezing. This actually happens more frequently along the east coast of the U.S. When big storms move south to north along the coastline (known as Nor’Easters), the flow around the storm pulls in air from the Atlantic Ocean. The oceanic air is very moist and can produce lots of snow. This is also bad at times, though, because the same oceanic air is also warm. If the air is warmer than freezing, the snowflakes that fall from the clouds will hit the warm air on their way to the ground and melt into raindrops.
As the raindrop falls, it might encounter air that is once again colder than freezing. Since colder air is heavier than warmer air, sometimes it can ‘hang out’ very close to the ground and refuse to move despite the best efforts of the warm air trying to push it out of the way.
So back to our example, the snowflake that melted into a raindrop would hit this colder air near the ground. If the cold air is thick enough and extends from the ground up a few thousand feet, the raindrop will have enough time to melt back into a solid ball of ice, which is called sleet. If the cold air is just near the ground and only extends a few hundred feet above the ground, the raindrop won’t spend enough time in the cold air to freeze back into sleet, but it will freeze when it hits a cold surface on the ground (power line, grass, road, etc).
We can all use weather models to find snow
Is it ever too cold to snow?
No. it can snow even at an incredibly cold temperature as long as there is some source of moisture in the air and a way to lift or cool the air. Still, most heavy snowfalls occur relatively warm. air temperatures near the ground. That’s because air can hold more water vapor at warmer temps.
When temperatures are above freezing
The snowflake will fall as a snowflake all the way toward the ground if the temperature at the ground is right around or just above freezing. The snowflake might not have enough time to melt as it falls since it’s only spending a short time in the warmer air before it hits the ground. So yes, as the graphic shows, snow can fall all the way to the ground even when temperatures are above freezing at the surface.
One last “cool fact,” (so to speak) is that the temperature can actually cool a few degrees due to evaporation if it’s just starting to snow.Some of the flakes will evaporate and this process actually cools the air if snowflakes fall into drier air. Keep an eye on the temperature when the first flakes begin to fly during the next snowstorm. When you catch sight of the first flakes, check back just a few minutes later if the temperature is just above freezing. Chances are the temperature fell a few degrees because of evaporation and hopefully, this gives us a better shot of having that snow accumulate into a meaningful powder day.
FAQs
Snow forms when the atmospheric temperature is at or below freezing (0°C or 32°F). If the ground temperature is at or below freezing, the snow will reach the ground. However, the snow can still reach the ground when the ground temperature is above freezing if the conditions are just right.
Can it snow when temps are above freezing? ›
If the above-freezing layer of air is limited to near the surface, the snow won't have much time to melt before it reaches the ground, allowing it to keep snowing even if your outside thermometer says 33, 34, or 35 degrees.
At what temperatures can it snow? ›
In order for the surface precipitation type to be snow, the atmospheric temperature (dashed red line in Figure 1) must be at or below 32°F (0°C) to ensure that no melting occurs. However, there are other special circ*mstances when snow can occur at the surface despite the entire atmosphere not being below freezing.
Will snow melt if it's above freezing? ›
If the air is warmer than freezing, the snowflakes that fall from the clouds will hit the warm air on their way to the ground and melt into raindrops. As the raindrop falls, it might encounter air that is once again colder than freezing.
What happens when snow falls into an area that is above freezing? ›
As snow falls into the layer of air where the temperature is above freezing, the snow flakes partially melt. As the precipitation reenters the air that is below freezing, the precipitation will re-freeze into ice pellets that bounce off the ground, commonly called sleet.
Can it snow if it's above 32 degrees? ›
GREAT FALLS — We are taught in grade school that water freezes at 32 degrees. Have you ever wondered why it can still snow at temperatures above the freezing point? Under the right circ*mstances, snow can actually fall with a temperature at the surface as high as 50 degrees.
What's the highest temperature it can snow? ›
It turns out that you don't need temperatures below freezing for snow to fall. In fact, snow can fall at temperatures as high as 50 degrees. Most residents of the northern United States have probably seen 40-degree snowfalls before, but snow at temperatures greater than 45 degrees is hard to come by.
How cold does it have to be to throw water and it freeze? ›
For boiling water to immediately freeze in mid air, the outside temperature needs to hit well below zero. Also, cold water will not freeze as boiling water will in those conditions. Some recommend -42 degrees, while other recommend -21 degrees.
How cold does it have to be to freeze water? ›
What Temperature Is Freezing? Water will freeze at 0 degrees Celsius, which is 32 degrees Fahrenheit. Any time the temperature drops below these, liquid water will begin to turn into ice. Water behaves very differently than other liquids.
How cold does it need to be to freeze? ›
Frost becomes more widespread when the temperature falls below 32°F with some freeze possible. A hard freeze is possible when temperatures fall below 28°F.
Since slush only forms at temperatures close to zero, it can change rapidly. If it gets a little warmer, the snow will immediately melt, but if it gets colder, it can quickly turn into ice. That's why slush can be classified as a weather hazard for transport.
At what height does snow not melt? ›
At or near the equator, it is typically situated at approximately 4,500 metres (15,000 ft) above sea level. As one moves towards the Tropic of Cancer and Tropic of Capricorn, the parameter at first increases: in the Himalayas the permanent snow line can be as high as 5,700 metres (19,000 feet).
Will snow melt at 9 degrees? ›
The melting point of snow, which is simply frozen water, is the same as that of its liquid form - 32 degrees Fahrenheit or 0 degrees Celsius.
What was the biggest ice storm in history? ›
On January 31, 1951, the costliest ice storm on record devastated an area of more than 100 miles wide from Louisiana to West Virginia. Twenty-five people lost their lives and approximately 500 more were injured in storm-related accidents.
Does rain help melt snow? ›
The findings show that warm rain falling on shallow snowpacks significantly speeds up melting by introducing additional heat. Conversely, freezing rain tends to form a crust over the snow, effectively insulating it and slowing down the melting process.
At what elevation does it start to snow? ›
Of course, snowfall in the coastal mountain ranges above 1500 – 2000 feet is almost an annual occurrence. What IS rare is snowfall at sea level, even in northern California.
Can it snow above 40 degrees? ›
Thus, if we wish to observe warm weather snow, very dry conditions are required. For example, if the ground humidity is only about 20% (very rare, because if there is precipitation, the atmosphere is generally wet!) then it could snow at 8°C (or 46°F for English users).
Why does snow often remain even when daytime temperatures are higher than the freezing temperature? ›
Other factors such as sunlight reflection, wind speed, aspect of slope, cloud cover, altitude, air pollution, wind breaks, and shadow cover can all contribute to the snow remaining on mountain slopes even when daytime temperatures are higher than freezing.
