<p>Large aggregate snowflakes an inch or so across formed from dendritic ice crystals sticking together are not uncommon, and according to research summarized by the New York Times, <a href="https://www.nytimes.com/2007/03/20/science/20snow.html" rel="nofollow noreferrer" title="William J. Broad, New York Times, 20 March 2007">&quot;Snowflakes as Big as Frisbees?&quot;</a> may be extremely unlikely but not impossible.</p>
<p>Larger aggregates <a href="https://www.research-collection.ethz.ch/handle/20.500.11850/144352" rel="nofollow noreferrer" title="Fall Velocity and Shape of Snowflakes, Monika Hanesch, Ph.D. Thesis, 1999, Swiss Federal Institute of Technology, Figure 6.1">fall faster</a>, so as they fall they will sweep out and agglomerate smaller snowflakes, growing ever larger until broken up by wind or they land. To get the largest aggregates, one needs temperatures around freezing so the snowflakes are sticky, a very large density of snowflakes, and relatively still air. There is no simple theoretical upper limit on their size.</p>
<p>The Montana report is definitely sketchy, but William Pike's 1988 article on <a href="http://www.ijmet.org/wp-content/uploads/2014/09/125.pdf" rel="nofollow noreferrer" title="W.S. Pike, Journal of Meteorology, UK, January 1988, Vol. 13, No. 125, pages 3-16">&quot;Unusually-Large Snowflakes&quot;</a> noted that there are reports from &quot;reliable observers&quot; of 2-6 inch diameter aggregate snowflakes. (Pike was inspired to do the research after he observed 2-3 inch snowflakes himself in Vancouver, Canada.)</p>
<p>As noted in the New York Times article, the problem with both forming and documenting large snowflakes is that they are so fragile. Large aggregates are weakly bound, can be easily broken by air movements, and disappear on landing.  This can be contrasted with large hailstones which can be very robust, so they stick around after landing and are easily photographed. Large snowflakes need to be imaged as they fall.</p>
<p>There are lots of videos online showing 1-2 inch aggregates falling. Interestingly, some of the best (such as <a href="https://youtu.be/adpOXRsUVz0?si=OkXqhIxNoxIZIz6G" rel="nofollow noreferrer">this</a> or <a href="https://www.facebook.com/viralhog/videos/285993029403702/" rel="nofollow noreferrer">this</a>) do come from Montana. The apparent lack of videos or images of larger aggregate snowflakes shows that they are clearly very rare.</p>

CC BY-SA 4.0
2024-02-01T20:40:07.993Z
I've seen snowflakes that are 2-3in myself, It's hard for me to believe that they could get larger than this, I would think that they would break apart. I also can't think of a way they would chain together after 3".
Voltage Spike
CC BY-SA 4.0
2024-02-02T04:07:45.457Z
@Voltage-Spike You might well be right, but estimating that limit for aggregate snowflakes is tough. In contrast, the maximum size of raindrops can be estimated since they flatten and break apart when drag forces overcome surface tension, but aggregate snowflakes don't have a simple uniform "surface tension" or density.
David Bailey
CC BY-SA 4.0
2024-02-01T19:28:11.873Z
2024-02-01T19:28:11.873Z
David Bailey
<blockquote>
<p>On the night of 27 January 1887, a fierce winter storm dropped
snowflakes described as &quot;larger than milk pans&quot; over the Clark Fork
River valley, in the vicinity of a ranch owned by Matt Coleman, near
Missoula in Montana, USA. Reports suggest that they were up to 1 ft 3
in (38 cm) wide and 8 in (20 cm) thick.</p>
</blockquote>
<p>Source: <a href="https://www.guinnessworldrecords.com/world-records/73325-largest-snowflake" rel="nofollow noreferrer">https://www.guinnessworldrecords.com/world-records/73325-largest-snowflake</a></p>
<p>That being said, its a report. And it's from 1887 with word of mouth. No pictures. Are there any documented cases of large snowflakes that are actually documented?</p>

CC BY-SA 4.0
2024-01-31T06:24:24.933Z
a snowflake is defined as one single ice crystal,i do not think the one in your question fit this definition.https://en.wikipedia.org/wiki/Snowflake you can take a look at the growth section of this wiki.
trond hansen
CC BY-SA 4.0
2024-01-31T09:11:16.217Z
The physics of that seems very challenging?
JeopardyTempest
CC BY-SA 4.0
2024-01-31T16:19:50.157Z
Actually, I was going to mention that... Back then it wasn't really a snowflake but they chain together and look like a single snowflake. I don't know if there is a term that defines chained snowflakes other than the word snowflake.
Voltage Spike
CC BY-SA 4.0
2024-01-31T16:20:50.083Z
@JeopardyTempest Yeah, and it isn't really well documented. No one really keeps logs of how big the chained flakes are, only single flakes.
Voltage Spike
CC BY-SA 4.0
2024-02-09T21:35:22.397Z
may be helpful https://www.npr.org/2023/12/25/1217356234/just-how-big-can-a-snowflake-get-it-depends-on-what-you-mean-by-snowflake
John
<snow>
Have snowflakes (or chained snowflakes) really been documented in sizes as 'large as milk pans'?
Voltage Spike
# Have snowflakes (or chained snowflakes) really been documented in sizes as 'large as milk pans'?

(Asked by: username_0 on 2024-01-30)

> On the night of 27 January 1887, a fierce winter storm dropped
> snowflakes described as "larger than milk pans" over the Clark Fork
> River valley, in the vicinity of a ranch owned by Matt Coleman, near
> Missoula in Montana, USA. Reports suggest that they were up to 1 ft 3
> in (38 cm) wide and 8 in (20 cm) thick.

Source: <https://www.guinnessworldrecords.com/world-records/73325-largest-snowflake>

That being said, its a report. And it's from 1887 with word of mouth. No pictures. Are there any documented cases of large snowflakes that are actually documented?

**Tags:** snow

> **Comments:**
> **username_1**: a snowflake is defined as one single ice crystal,i do not think the one in your question fit this definition.https://en.wikipedia.org/wiki/Snowflake you can take a look at the growth section of this wiki.  
> **username_2**: The physics of that seems very challenging?  
> **username_0**: Actually, I was going to mention that... Back then it wasn't really a snowflake but they chain together and look like a single snowflake. I don't know if there is a term that defines chained snowflakes other than the word snowflake.  
> **username_0**: @username_2 Yeah, and it isn't really well documented. No one really keeps logs of how big the chained flakes are, only single flakes.  
> **username_3**: may be helpful https://www.npr.org/2023/12/25/1217356234/just-how-big-can-a-snowflake-get-it-depends-on-what-you-mean-by-snowflake  

---

## 1 answers

### Answer by username_4 on 2024-02-01. Score: 2 | Accepted answer

Large aggregate snowflakes an inch or so across formed from dendritic ice crystals sticking together are not uncommon, and according to research summarized by the New York Times, ["Snowflakes as Big as Frisbees?"](https://www.nytimes.com/2007/03/20/science/20snow.html "William J. Broad, New York Times, 20 March 2007") may be extremely unlikely but not impossible.

Larger aggregates [fall faster](https://www.research-collection.ethz.ch/handle/20.500.11850/144352 "Fall Velocity and Shape of Snowflakes, Monika Hanesch, Ph.D. Thesis, 1999, Swiss Federal Institute of Technology, Figure 6.1"), so as they fall they will sweep out and agglomerate smaller snowflakes, growing ever larger until broken up by wind or they land. To get the largest aggregates, one needs temperatures around freezing so the snowflakes are sticky, a very large density of snowflakes, and relatively still air. There is no simple theoretical upper limit on their size.

The Montana report is definitely sketchy, but William Pike's 1988 article on ["Unusually-Large Snowflakes"](http://www.ijmet.org/wp-content/uploads/2014/09/125.pdf "W.S. Pike, Journal of Meteorology, UK, January 1988, Vol. 13, No. 125, pages 3-16") noted that there are reports from "reliable observers" of 2-6 inch diameter aggregate snowflakes. (Pike was inspired to do the research after he observed 2-3 inch snowflakes himself in Vancouver, Canada.)

As noted in the New York Times article, the problem with both forming and documenting large snowflakes is that they are so fragile. Large aggregates are weakly bound, can be easily broken by air movements, and disappear on landing. This can be contrasted with large hailstones which can be very robust, so they stick around after landing and are easily photographed. Large snowflakes need to be imaged as they fall.

There are lots of videos online showing 1-2 inch aggregates falling. Interestingly, some of the best (such as [this](https://youtu.be/adpOXRsUVz0?si=OkXqhIxNoxIZIz6G) or [this](https://www.facebook.com/viralhog/videos/285993029403702/)) do come from Montana. The apparent lack of videos or images of larger aggregate snowflakes shows that they are clearly very rare.

> **Comments:**
> **username_0**: I've seen snowflakes that are 2-3in myself, It's hard for me to believe that they could get larger than this, I would think that they would break apart. I also can't think of a way they would chain together after 3".  
> **username_4**: @username_0-username_0 You might well be right, but estimating that limit for aggregate snowflakes is tough. In contrast, the maximum size of raindrops can be estimated since they flatten and break apart when drag forces overcome surface tension, but aggregate snowflakes don't have a simple uniform "surface tension" or density.  

---

