First Freeze Date for U.S. - Map

Last Freeze Date for U.S. - Map

While these maps show the average timeframe of the first and last freeze across the United States, each year’s actual conditions may vary widely based on weather patterns. Wondering why no data on Alaska and Hawaii? The unique climates of these regions pose a problem in calculating the average date of the first and last freeze. Nearly all of Alaska falls into the “too cold to compute” category, meaning that the state is likely to see freezing temperatures year-round. At the opposite end of the spectrum, all of Hawaii, other than the highest elevations of the state, fall into the “too warm to compute” category, meaning that they very rarely or never see freezing temperatures.

First and Last Frost Dates

There is a difference between the last/first Freeze date and the last/first Frost date, as we can see frost with temps above freezing (37 degrees is about the highest*). Plus all of the above maps aren't really 100% true for our area, since conditions vary depending on exactly where in the greater Crestone/Baca you live when it comes to these different events. Yet while more of us in this area live in the foothills and not in the valley, when it comes to frost (unlike snowfall), most of our foothills see the same first/last frost dates that are also seen in the SLV. For the frost map, most of our area is in area 4, other than our mountains are in area 3. Do note that they got the dates wrong for area 3, as our highest peaks above 13,000 and 14,000 feet can see frost year round, as all such peaks in the Rockies can.

*the reason for this is that we measure the temperature at a height of about 5 feet (and why it's called the "air temperature"), and at ground level it can be a few degrees colder at the very same time, since cold air sinks. This happens often in the spring and fall, so do keep that in mind, since your garden sits on the ground!

What does a "hard freeze" mean? Some plants can handle a light freeze of around 32°(F) or even a bit colder, but not a hard freeze. A hard freeze occurs when the temperature reaches 28°(F) or lower for at least a few hours. It usually means that many types of plants and most seasonal vegetation will be destroyed.

Last Deer Date

I received an email suggesting I also list the "last deer date" on this page. This page was made mainly for local gardeners who each late spring wonder just how early they might start their gardens. Of course, the many deer we have in the greater Crestone area causes problems for local gardens. But yes, in most of the Baca, the deer leave for the summer, keeping our gardens safe from these hungry animals. But it depends on where you are located as to when you will see less deer. Rule of thumb is to go by your elevation, since the deer live higher up in the summer months. If you live below 9000 feet, they usually leave around or just after June 1 - in most years. Over that elevation, or in the town of Crestone,  you may see deer year-round.

The deer usually return by the end of September (below 8500 feet, mid September above), pretty much after the growing season is over, so the late spring is the time to be ready for their visits to your garden.

Crestone's Deer in Spring

April, 2003

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