Frost Dates: First and last frost dates for Hermit, CO

ℹ️ How to read these charts for the spring

As spring unfolds, the risk of frost gradually decreases each day until your tender plants are finally safe. The probabilities shown in the chart help you make smart decisions about when to plant.

While frost typically forms at 32°F, tender plants can be damaged even when temperatures are slightly higher. Air temperatures are often measured several feet above the ground, but temperatures at plant level can be several degrees colder. Protected areas like porches help by blocking radiational cooling. Given these variables, we consider 36°F the "caution zone" for frost-sensitive plants.

Key dates for your spring planting:

  • By July 29, you have a 90% chance of being frost-free — this is your "safe date" for planting tender crops
  • Around July 10, there's a 50/50 chance of frost — check weather forecasts carefully if planting now
  • Before June 28, there's still an 80% risk of frost — too early for tomatoes and other tender plants unless you're prepared to protect them

If the 10-day forecast shows no temperatures below 40°F, you might safely plant earlier than the above dates suggest. Many gardeners watch for this weather window to get a head start on the growing season.

In the Spring
Temperature 10% 20% 30% 40% 50% 60% 70% 80% 90%
Last 16° May 7 May 2 Apr 28 Apr 25 Apr 21 Apr 18 Apr 15 Apr 11 Apr 6
Last 20° May 21 May 16 May 12 May 9 May 6 May 3 Apr 30 Apr 26 Apr 21
Last 24° Jun 12 Jun 5 May 30 May 26 May 22 May 18 May 14 May 9 May 1
Last 28° Jun 27 Jun 22 Jun 18 Jun 15 Jun 12 Jun 9 Jun 6 Jun 2 May 27
Last 32° Jul 9 Jul 4 Jul 1 Jun 28 Jun 25 Jun 22 Jun 19 Jun 16 Jun 11
Last 36° Jul 29 Jul 22 Jul 18 Jul 14 Jul 10 Jul 7 Jul 3 Jun 28 Jun 22

ℹ️ How to read these charts for the fall

As summer ends in Hermit, CO, nighttime temperatures begin to drop, and your risk of frost increases with each passing day. Knowing when to expect frost helps you harvest sensitive crops and extend your growing season with protection methods.

The chart below shows the probability of experiencing specific temperatures on various dates. Here's what this means for your garden:

1
Early warning: Around August 20, there's a 20% chance of 32°F — start monitoring forecasts and have plant covers ready
2
Decision time: By September 2, there's a 50% chance of frost — harvest tomatoes, peppers, and other tender crops or prepare protection
3
Last chance: By September 16, there's an 80% chance of seeing 32°F — most tender plants will be damaged without protection
4
Another perspective: You have only a 1 in 5 chance of making it past September 16 without a freezing night

These probabilities help you time your end-of-season harvests and know when to apply protective measures like row covers, cloches, or cold frames to extend your harvest.

In the Fall
Temperature 10% 20% 30% 40% 50% 60% 70% 80% 90%
First 16° Sep 29 Oct 6 Oct 11 Oct 15 Oct 19 Oct 23 Oct 27 Nov 1 Nov 7
First 20° Sep 23 Sep 29 Oct 4 Oct 8 Oct 11 Oct 15 Oct 19 Oct 24 Oct 30
First 24° Sep 15 Sep 20 Sep 23 Sep 26 Sep 28 Oct 1 Oct 4 Oct 7 Oct 11
First 28° Sep 3 Sep 8 Sep 11 Sep 14 Sep 17 Sep 20 Sep 23 Sep 26 Oct 1
First 32° Aug 13 Aug 20 Aug 25 Aug 29 Sep 2 Sep 6 Sep 11 Sep 16 Sep 23
First 36° Jul 31 Aug 5 Aug 9 Aug 13 Aug 16 Aug 19 Aug 22 Aug 26 Sep 1

📍 Frost Dates for other nearby locations

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Data is provided by the NOAA National Centers for Environmental Information.