First and last freeze/frost dates for Fort Collins, CO ,United StatesFirst and last freeze/frost dates for:
Detailed station data* follows:
Ft Collins, CO (Larimer county):
|Spring 32°||May 15||May 11||May 8||May 6||May 4||May 2||Apr 30||Apr 27||Apr 23|
|Spring 28°||May 2||Apr 27||Apr 24||Apr 21||Apr 18||Apr 16||Apr 13||Apr 10||Apr 5|
|Spring 24°||Apr 20||Apr 15||Apr 12||Apr 9||Apr 7||Apr 4||Apr 1||Mar 29||Mar 25|
|Fall 32°||Sep 18||Sep 23||Sep 26||Sep 29||Oct 2||Oct 5||Oct 8||Oct 12||Oct 17|
|Fall 28°||Sep 24||Sep 30||Oct 4||Oct 7||Oct 10||Oct 13||Oct 17||Oct 21||Oct 26|
|Fall 24°||Oct 4||Oct 10||Oct 14||Oct 18||Oct 21||Oct 25||Oct 28||Oct 31||Nov 6|
Waterdale, CO (Larimer county):
|Spring 32°||May 18||May 14||May 12||May 9||May 8||May 6||May 3||May 1||Apr 27|
|Spring 28°||May 10||May 6||May 3||May 1||Apr 29||Apr 26||Apr 24||Apr 21||Apr 17|
|Spring 24°||Apr 29||Apr 25||Apr 21||Apr 19||Apr 16||Apr 13||Apr 10||Apr 7||Apr 3|
|Fall 32°||Sep 16||Sep 20||Sep 22||Sep 25||Sep 27||Sep 29||Oct 2||Oct 5||Oct 9|
|Fall 28°||Sep 22||Sep 27||Oct 1||Oct 5||Oct 8||Oct 11||Oct 14||Oct 18||Oct 24|
|Fall 24°||Oct 1||Oct 7||Oct 11||Oct 15||Oct 18||Oct 22||Oct 25||Oct 30||Nov 3|
Longmont 2 Ese, CO (Boulder county):
|Spring 32°||May 18||May 13||May 10||May 7||May 5||May 2||Apr 29||Apr 26||Apr 22|
|Spring 28°||May 8||May 3||Apr 30||Apr 27||Apr 24||Apr 22||Apr 19||Apr 15||Apr 10|
|Spring 24°||May 1||Apr 26||Apr 23||Apr 20||Apr 17||Apr 14||Apr 11||Apr 7||Apr 2|
|Fall 32°||Sep 15||Sep 19||Sep 23||Sep 25||Sep 28||Sep 30||Oct 3||Oct 6||Oct 10|
|Fall 28°||Sep 22||Sep 28||Oct 2||Oct 5||Oct 8||Oct 11||Oct 15||Oct 19||Oct 24|
|Fall 24°||Sep 28||Oct 4||Oct 8||Oct 12||Oct 16||Oct 19||Oct 23||Oct 27||Nov 1|
* This station data is available courtesy the National Climatic Data Center.
For each weather station, you will see a temperature along with tables of data organized into percentage columns. The percentage column tells you the probability that you will experience that row's temperature on or near that date. Here are two examples to help you determine your probable last frost and first freeze dates.
Example 1 (Last Frost). In the Spring 32° row, if you have "Apr 15" under the 50% column, that means you have a 50% chance of seeing frost on or before April 15th.
Example 2 (First Freeze). In the Fall 24° row, if you have "Dec 1" under the 90% column, that means you have a 90% chance of seeing 24 degrees on or after December 1st.
Empty cells indicate you have a less than 10% chance of ever seeing that temperature.