Frost Dates: First and last frost dates for Altus Dam, OK

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 April 23, you have a 90% chance of being frost-free — this is your "safe date" for planting tender crops
  • Around April 10, there's a 50/50 chance of frost — check weather forecasts carefully if planting now
  • Before April 1, 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° Mar 8 Feb 27 Feb 21 Feb 15 Feb 10 Feb 5 Jan 31 Jan 24 Jan 13
Last 20° Mar 13 Mar 4 Feb 26 Feb 21 Feb 16 Feb 11 Feb 6 Jan 31 Jan 22
Last 24° Mar 31 Mar 23 Mar 17 Mar 11 Mar 7 Mar 2 Feb 24 Feb 18 Feb 10
Last 28° Apr 10 Apr 4 Mar 30 Mar 26 Mar 22 Mar 18 Mar 14 Mar 9 Mar 2
Last 32° Apr 13 Apr 9 Apr 6 Apr 4 Apr 2 Mar 30 Mar 28 Mar 25 Mar 22
Last 36° Apr 23 Apr 19 Apr 15 Apr 12 Apr 10 Apr 7 Apr 4 Apr 1 Mar 27

ℹ️ How to read these charts for the fall

As summer ends in Altus Dam, OK, 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 October 22, there's a 20% chance of 32°F — start monitoring forecasts and have plant covers ready
2
Decision time: By November 3, there's a 50% chance of frost — harvest tomatoes, peppers, and other tender crops or prepare protection
3
Last chance: By November 15, 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 November 15 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° Nov 17 Nov 28 Dec 5 Dec 12 Dec 18 Dec 24 Dec 31 Jan 8 Jan 21
First 20° Nov 11 Nov 20 Nov 25 Dec 1 Dec 5 Dec 10 Dec 15 Dec 21 Dec 29
First 24° Oct 31 Nov 8 Nov 14 Nov 18 Nov 23 Nov 27 Dec 2 Dec 8 Dec 16
First 28° Oct 23 Oct 30 Nov 3 Nov 7 Nov 11 Nov 14 Nov 18 Nov 23 Nov 29
First 32° Oct 15 Oct 22 Oct 26 Oct 30 Nov 3 Nov 7 Nov 11 Nov 15 Nov 21
First 36° Oct 3 Oct 9 Oct 14 Oct 18 Oct 22 Oct 25 Oct 29 Nov 3 Nov 9

📍 Frost Dates for other nearby locations

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