skip to Main Content


Well, Frosty the Snowman may not have been really frosty!! It might spoil some cherished childhood memories of singing his song, but no — Frosty the Snowman probably wasn’t frosty. Snow is a bit different than the branching, spiky ice crystals of hoar frost, though the two are often seen together.

Frost vs. Snow

The main difference between the two is how they form. Frost forms like dew, in that it appears on a surface of the ground or the hood of a car. When a surface is colder than the dew point of the air around it, moisture collects on that surface. When that temperature is below freezing, that moisture takes the form of ice crystals. By contrast, snow condenses around particles in clouds and falls to earth as a precipitate.

Hoarfrost, Surface Hoar, and Other Varieties

There are several different ways that ice crystals can grow, including:

  • Windows develop ice crystals when they are exposed to freezing temperatures outside, and warmer, the moister air inside. The condensation collects on the surface of the window in lacy, fern-like patterns.
  • Hoarfrost develops when there is a particularly ample source of humid air. Hoar frost crystals are particularly large and relatively common near bodies of water or other places where there’s a lot of moisture.
  • Surface hoar is easy to confuse with snow, as it often forms atop snowdrifts. As snow evaporates during the day, it releases humidity into the layer of air right atop the drift. When temperatures drop at night, this humidity condenses on the re-frozen surface of the snow bank as small, glittery ice crystals.
  • Crevasse Hoar frost develops in glacial crevasses. There, water vapor builds up from sublimating ice, and the freezing temperatures and calm air allow for an ideal environment for hoarfrost to grow.

When Warnings Occur

Guidelines for frost warnings or advisories state that they should be issued when ice crystals are predicted to form at three or more observational sites, typically in late spring to early autumn. They are of particular interest to farmers and gardeners, as they can affect planting and harvesting times or kill plants. The first widespread freeze usually signals the end of the growing season, and meteorologists typically stop issuing warnings until the following spring.

If you’re not a weather frost expert, it can sometimes be difficult to tell surface Hoar frost from snow. One look at the lacy patterns on windows or the large, pointy crystals of hoar frost shows that they wouldn’t be very good building material for a snowman, however magical he might be! To learn more about snow and ice removal from the snow, ice and frost experts, contact our certified snow professionals today for a consultation.

DISCLAIMER: Information contained in this Website and blog is intended for informational purposes only and do not necessarily reflect the direct opinions, views or practices of Swenson Consulting or its consultants. The individuals who maintain this blog work for Swenson Consulting. The information, comments and links posted on this blog do not constitute legal advice. No attorney-client relationship has been or will be formed by any communication(s) to, from or with the blog and/or the blogger. All decisions relating to the content of the website blog belong to the blogger and management company responsible for the blog for the purpose of aggregating relative industry specific information related to snow removal.

Back To Top