The first freezing temperatures of the season were recorded in western Kansas this past weekend, marking the end of the growing season in many areas—especially outside urban heat islands and regions with heavier vegetation (Figure 1). The Hamilton County Mesonet site near Syracuse fell to 30 degrees just before midnight on October 18. By the next morning, 30 sites were below freezing. On the mornings of October 21 and 22, additional freezes were recorded across northern Kansas. As of October 22, 40 sites across the state have recorded at least one freeze.
With more locations expected to approach the 32°F mark this week, now is an ideal time to explore the Kansas Mesonet’s Freeze Monitor (https://mesonet.k-state.edu/airtemp/min/hoursbelow/. This tool allows users to track real-time conditions and compare current frost and freeze events to long-term climatology. How does this year’s first freeze compare to average? Has your area dropped below freezing yet—and for how long? The Freeze Monitor provides quick answers to these questions and more.
Figure 1. The lowest temperature recorded at each Kansas Mesonet site so far this fall (September 1 through October 22, 2025). Locations with temperatures inside squares have recorded a freeze this fall. Underneath each symbol is the date on which the plotted lowest temperature occurred. Map by Matthew Sittel, Weather Data Library.
The average freeze date (32°F) in northwest Kansas is as early as the last week in September (Figure 2). However, southeast Kansas does not usually see freezing temperatures until the end of October. You can find the average first freeze dates by location here: https://mesonet.k-state.edu/airtemp/min/hoursbelow/#tab=table-tab&mtIndex=6. The “Table” tab lists the average dates on the right side (Figure 3). Average dates for the first occurrence of 28°F temperatures are even later (Figure 4).
Figure 2. Average fall freeze dates for Kansas. Source: Kansas Weather Data Library.
Figure 3. First freeze date averages for all Mesonet stations as found on the “Table” tab. Source: Kansas Mesonet.
Figure 4. Average 28oF freeze dates for Kansas. Map created by Matthew Sittel, Kansas Weather Data Library.
Historically, almost all parts of the state have recorded freezing temperatures as early as September. The earliest first freeze on record in Kansas was September 3, 1974, when many stations dropped below freezing. However, this year, the first freezes have fallen as much as two weeks later than normal in the northwest and a week later than normal in north-central Kansas.
Common question: “How cold did it get?”
The Freeze Monitor tool displays the coldest temperatures observed across Kansas during the previous two weeks (the most recent freeze event during the previous two weeks is displayed; Figure 5). It also tracks the first fall freeze date for each station for comparison to local climatology in a table (https://mesonet.k-state.edu/airtemp/min/hoursbelow/#tab=table-tab&mtIndex=6) as seen in Figure 3. Data updates every twenty minutes on both the map and the table.
Common question: “Was it cold long enough to damage crops?”
Another tool important for producers and gardeners is the duration below freezing, as some crops and commodities have lower thresholds for damage. This feature allows users to select options to view maps/data of the “hours below 32°F”, “hours below 24°F,” and the “hours below 12°F”). While all three are of interest, the lower two thresholds are of great importance to wheat growers later into the fall/winter season.
Figure 5. View of the Freeze Monitor webpage on October 22, 2025. Wallace (selected station) shows a freeze event on October 21, 2025. The map represents the latest freeze events at these locations since October 8, 2025. Source: https://mesonet.k-state.edu/airtemp/min/hoursbelow/#tab=table-tab&mtIndex=0
Common question: “How long has it been above freezing?”
The freeze monitor can also track the duration of days since the last freeze or below the 24°F and 12°F thresholds. This is ideal for determining the first freeze and estimating the length of the growing season. You can find “days since” using this link: https://mesonet.k-state.edu/airtemp/min/hoursbelow/#tab=table-tab&mtIndex=6. The last freeze in the spring occurred in mid-April, and with the later-than-normal freeze for most of Kansas thus far, this has resulted in a significantly longer growing season than normal. Many locations were at 180+ days without freezing temperatures as can be observed in the ”Days Since 32” option (Figure 6).
Figure 6. Number of days since the last freeze as of October 5, 2023. Find this information here: https://mesonet.k-state.edu/airtemp/min/hoursbelow/#tab=table-tab&mtIndex=6.
The data displayed in the tables below the maps can be sorted. Clicking on the header of a particular column will sort the table by that column. This makes it much easier to see what area was the coldest in the state, as well as the earliest freeze and earliest climatological freeze data. There are several download options, including table and chart data and images of the maps.
The Freeze Monitor remains operational throughout the winter and is available for the 24°F and 12°F thresholds, in addition to the 32°F threshold, for those arctic air masses. As we approach spring, the Freeze Monitor will be updated to display the spring freeze climatology.
Chip Redmond, Weather Data Library/Mesonet
christopherredmond@ksu.edu
Matthew Sittel, Assistant State Climatologist
msittel@ksu.edu
Dan Regier, Weather Data Library/Mesonet
regierdp@ksu.edu